diff --git a/src/entities/PathComponent.cpp b/src/entities/PathComponent.cpp
index fea66a1d..2d6f25c8 100644
--- a/src/entities/PathComponent.cpp
+++ b/src/entities/PathComponent.cpp
@@ -62,14 +62,54 @@ void PathComponent::Begin() {
 
     animationPath_->clear();
 
-    const std::vector<double>& steps = timeStep_->GetSteps();
+    // 优先使用路径文件的时间列；若不存在则按当前时间范围等间距生成时间点
+    std::vector<double> mappedSteps;
+    const bool hasPathTimes = transformPath_ && !transformPath_->GetTimes().empty();
+    double rangeMin = 0.0, rangeMax = 0.0, rangeStep = 0.0;
+    timeStep_->GetRange(rangeMin, rangeMax, rangeStep);
+    if (hasPathTimes) {
+        const auto& times = transformPath_->GetTimes();
+        if (timeStep_->HasManualRange()) {
+            // 将路径文件时间列线性映射到用户指定的手动区间，保证相对时间关系不变
+            double srcMin = times.front();
+            double srcMax = times.back();
+            double dstMin = timeStep_->GetManualStart();
+            double dstMax = timeStep_->GetManualEnd();
+            double srcSpan = std::max(1e-9, srcMax - srcMin);
+            mappedSteps.reserve(times.size());
+            for (double t : times) {
+                double alpha = (t - srcMin) / srcSpan;
+                mappedSteps.push_back(dstMin + alpha * (dstMax - dstMin));
+            }
+        } else {
+            mappedSteps = times;
+        }
+    } else {
+        const std::vector<Transform>& transforms = transformPath_->GetTransforms();
+        int num = (int)transforms.size();
+        if (num > 0) {
+            mappedSteps.resize(num);
+            double start = timeStep_->HasManualRange() ? timeStep_->GetManualStart() : rangeMin;
+            double end = timeStep_->HasManualRange() ? timeStep_->GetManualEnd() : rangeMax;
+            double step = rangeStep;
+            // 若步长无效，则回退为均匀分布
+            if (step <= 0.0) {
+                step = (num > 1) ? std::max(0.0, (end - start)) / double(num - 1) : 0.0;
+            }
+            for (int i = 0; i < num; ++i) {
+                double t = start + step * double(i);
+                if (t > end) t = end;
+                mappedSteps[i] = t;
+            }
+        }
+    }
     const std::vector<Transform>& transforms = transformPath_->GetTransforms();
-    int num = std::min(steps.size(), transforms.size());
+    int num = std::min(mappedSteps.size(), transforms.size());
     for (int index = 0; index < num; ++index) {
         const Transform& transform = transforms[index];
         osg::AnimationPath::ControlPoint controlPoint(transform.GetLocation() /*+ osg::Vec3(index * 10, 0, 0)*/,
             OsgUtils::HPRToQuat(transform.GetRotation()), transform.GetScale());
-        animationPath_->insert(steps[index], controlPoint);
+        animationPath_->insert(mappedSteps[index], controlPoint);
     }
 
     deltaTime_ = 0;
diff --git a/src/ui/Menu/PlayManagerMenu.cpp b/src/ui/Menu/PlayManagerMenu.cpp
index c79ae567..77fe6401 100644
--- a/src/ui/Menu/PlayManagerMenu.cpp
+++ b/src/ui/Menu/PlayManagerMenu.cpp
@@ -139,6 +139,16 @@ void PlayManagerMenu::OnTimestepChanged(Timestep* timestep) {
         ui->lbUp->setText(QString("x%1").arg(step));
         }
     );
+    // 当时间范围更新（例如用户在属性面板设置了起止时间）时，刷新显示与滑条范围
+    connect(timestep, &Timestep::RangeChanged, [this](double minTime, double maxTime, double step) {
+        minTime_ = minTime;
+        maxTime_ = maxTime;
+        ui->lbtime->setText(QString::number(minTime_, 'f', 3));
+        ui->lbtimeTotal->setText(QString("/%1(s)").arg(maxTime_));
+        ui->lbUp->setText(QString("x%1").arg(step));
+        ui->horizontalSlider->setRange((int)(minTime_ * 1000), (int)(maxTime_ * 1000));
+        ui->horizontalSlider->setValue((int)(minTime_ * 1000));
+    });
     
     connect(timestep, &Timestep::StatusChanged, [this](int statue) {
         Timestep::PlayStatus state = static_cast<Timestep::PlayStatus>(statue);
diff --git a/src/ui/PropertyBrowser/qtpropertymanager.cpp b/src/ui/PropertyBrowser/qtpropertymanager.cpp
index fccaf477..b2c485bd 100644
--- a/src/ui/PropertyBrowser/qtpropertymanager.cpp
+++ b/src/ui/PropertyBrowser/qtpropertymanager.cpp
@@ -7916,7 +7916,6 @@ public:
 
     QMap<const QtProperty*, QtProperty*> m_properyToName;
     QMap<const QtProperty*, QtProperty*> m_properyToDescription;
-    QMap<const QtProperty*, QtProperty*> m_properyToTimestep;
     QMap<const QtProperty*, QtProperty*> m_properyToSimMatlab;
     QMap<const QtProperty*, QtProperty*> m_properyToMatlabParam;
     QMap<const QtProperty*, QtProperty*> m_properyToWavePath;
@@ -7926,7 +7925,6 @@ public:
 
     QMap<const QtProperty*, QtProperty*> m_nameToPropery;
     QMap<const QtProperty*, QtProperty*> m_descriptionToPropery;
-    QMap<const QtProperty*, QtProperty*> m_timestepToPropery;
     QMap<const QtProperty*, QtProperty*> m_simMatlabToPropery;
     QMap<const QtProperty*, QtProperty*> m_matlabParamToPropery;
     QMap<const QtProperty*, QtProperty*> m_wavePathToPropery;
@@ -7951,6 +7949,16 @@ public:
     QMap<const QtProperty*, QtProperty*> m_properyToHomeRange;
     QMap<const QtProperty*, QtProperty*> m_homeRangeToPropery;
 
+    // Simulation Time group (manual range)
+    QMap<const QtProperty*, QtProperty*> m_properyToSimTimeGroup;
+    QMap<const QtProperty*, QtProperty*> m_simTimeGroupToPropery;
+    QMap<const QtProperty*, QtProperty*> m_properyToSimStart;
+    QMap<const QtProperty*, QtProperty*> m_simStartToPropery;
+    QMap<const QtProperty*, QtProperty*> m_properyToSimEnd;
+    QMap<const QtProperty*, QtProperty*> m_simEndToPropery;
+    QMap<const QtProperty*, QtProperty*> m_properyToSimStep;
+    QMap<const QtProperty*, QtProperty*> m_simStepToPropery;
+
     // Grouped file entries: Curve
     QMap<const QtProperty*, QtProperty*> m_properyToCurveGroup;
     QMap<const QtProperty*, QtProperty*> m_curveGroupToPropery;
@@ -8015,10 +8023,6 @@ void QtWorkspacePropertyManagerPrivate::slotStringChanged(QtProperty* property,
         QWorkspaceAttribute c = m_values[prop];
         c.SetDescription(value);
         q_ptr->setValue(prop, c);
-    } else if (QtProperty* prop = m_timestepToPropery.value(property, 0)) {
-        QWorkspaceAttribute c = m_values[prop];
-        c.SetTimeStep(value);
-        q_ptr->setValue(prop, c);
     } else if (QtProperty* prop = m_commondPathToPropery.value(property, 0)) {
         QWorkspaceAttribute c = m_values[prop];
         c.SetCommondFilePath(value);
@@ -8145,6 +8149,18 @@ void QtWorkspacePropertyManagerPrivate::slotDoubleChanged(QtProperty* property,
         QWorkspaceAttribute c = m_values[prop];
         c.SetHomeViewpointRange(value);
         q_ptr->setValue(prop, c);
+    } else if (QtProperty* prop = m_simStartToPropery.value(property, 0)) {
+        QWorkspaceAttribute c = m_values[prop];
+        c.SetSimulationStart(value);
+        q_ptr->setValue(prop, c);
+    } else if (QtProperty* prop = m_simEndToPropery.value(property, 0)) {
+        QWorkspaceAttribute c = m_values[prop];
+        c.SetSimulationEnd(value);
+        q_ptr->setValue(prop, c);
+    } else if (QtProperty* prop = m_simStepToPropery.value(property, 0)) {
+        QWorkspaceAttribute c = m_values[prop];
+        c.SetSimulationStep(value);
+        q_ptr->setValue(prop, c);
     }
 }
 
@@ -8159,10 +8175,7 @@ void QtWorkspacePropertyManagerPrivate::slotPropertyDestroyed(QtProperty* proper
 		m_descriptionToPropery.remove(property);
 	}
     
-    if (QtProperty* subProp = m_timestepToPropery.value(property, nullptr)) {
-        m_timestepToPropery[subProp] = 0;
-        m_timestepToPropery.remove(property);
-    }
+    // Removed: timestep property mapping cleanup (no longer tracked)
 
     if (QtProperty* subProp = m_simMatlabToPropery.value(property, nullptr)) {
         m_simMatlabToPropery[subProp] = 0;
@@ -8184,6 +8197,44 @@ void QtWorkspacePropertyManagerPrivate::slotPropertyDestroyed(QtProperty* proper
         m_rdPathToPropery[subProp] = 0;
         m_rdPathToPropery.remove(property);
     }
+    // HomeViewpoint numeric children
+    if (QtProperty* subProp = m_homeLonToPropery.value(property, nullptr)) {
+        m_homeLonToPropery[subProp] = 0;
+        m_homeLonToPropery.remove(property);
+    }
+    if (QtProperty* subProp = m_homeLatToPropery.value(property, nullptr)) {
+        m_homeLatToPropery[subProp] = 0;
+        m_homeLatToPropery.remove(property);
+    }
+    if (QtProperty* subProp = m_homeAltToPropery.value(property, nullptr)) {
+        m_homeAltToPropery[subProp] = 0;
+        m_homeAltToPropery.remove(property);
+    }
+    if (QtProperty* subProp = m_homeHeadingToPropery.value(property, nullptr)) {
+        m_homeHeadingToPropery[subProp] = 0;
+        m_homeHeadingToPropery.remove(property);
+    }
+    if (QtProperty* subProp = m_homePitchToPropery.value(property, nullptr)) {
+        m_homePitchToPropery[subProp] = 0;
+        m_homePitchToPropery.remove(property);
+    }
+    if (QtProperty* subProp = m_homeRangeToPropery.value(property, nullptr)) {
+        m_homeRangeToPropery[subProp] = 0;
+        m_homeRangeToPropery.remove(property);
+    }
+    // Simulation Time children
+    if (QtProperty* subProp = m_simStartToPropery.value(property, nullptr)) {
+        m_simStartToPropery[subProp] = 0;
+        m_simStartToPropery.remove(property);
+    }
+    if (QtProperty* subProp = m_simEndToPropery.value(property, nullptr)) {
+        m_simEndToPropery[subProp] = 0;
+        m_simEndToPropery.remove(property);
+    }
+    if (QtProperty* subProp = m_simStepToPropery.value(property, nullptr)) {
+        m_simStepToPropery[subProp] = 0;
+        m_simStepToPropery.remove(property);
+    }
 }
 
 QtWorkspacePropertyManager::QtWorkspacePropertyManager(QObject* parent)
@@ -8286,7 +8337,6 @@ void QtWorkspacePropertyManager::setValue(QtProperty* property, const QWorkspace
 
     d_ptr->m_stringProperyManager->setValue(d_ptr->m_properyToName[property], value.GetName());
     d_ptr->m_stringProperyManager->setValue(d_ptr->m_properyToDescription[property], value.GetDescription());
-    d_ptr->m_filesProperyManager->setValue(d_ptr->m_properyToTimestep[property], value.GetTimeStep());
     d_ptr->m_filesProperyManager->setValue(d_ptr->m_properyToCommondPath[property], value.GetCommondFilePath());
     // Sync HomeViewpoint numeric fields
     if (QtProperty* p = d_ptr->m_properyToHomeLon.value(property, nullptr))
@@ -8301,6 +8351,13 @@ void QtWorkspacePropertyManager::setValue(QtProperty* property, const QWorkspace
         d_ptr->m_doubleProperyManager->setValueOnly(p, value.GetHomeViewpointPitch());
     if (QtProperty* p = d_ptr->m_properyToHomeRange.value(property, nullptr))
         d_ptr->m_doubleProperyManager->setValueOnly(p, value.GetHomeViewpointRange());
+    // Sync Simulation Time Start/End
+    if (QtProperty* p = d_ptr->m_properyToSimStart.value(property, nullptr))
+        d_ptr->m_doubleProperyManager->setValueOnly(p, value.GetSimulationStart());
+    if (QtProperty* p = d_ptr->m_properyToSimEnd.value(property, nullptr))
+        d_ptr->m_doubleProperyManager->setValueOnly(p, value.GetSimulationEnd());
+    if (QtProperty* p = d_ptr->m_properyToSimStep.value(property, nullptr))
+        d_ptr->m_doubleProperyManager->setValueOnly(p, value.GetSimulationStep());
 
     auto syncGroup = [&](FileEntryType type,
                          QMap<const QtProperty*, QtProperty*>& propToGroup,
@@ -8383,12 +8440,7 @@ void QtWorkspacePropertyManager::initializeProperty(QtProperty* property) {
 	d_ptr->m_descriptionToPropery[prop] = property;
 	property->addSubProperty(prop);
 
-    prop = d_ptr->m_filesProperyManager->addProperty();
-    prop->setPropertyName(tr("Timestep"));
-    d_ptr->m_filesProperyManager->setValueOnly(prop, val.GetTimeStep());
-    d_ptr->m_properyToTimestep[property] = prop;
-    d_ptr->m_timestepToPropery[prop] = property;
-    property->addSubProperty(prop);
+    // Removed: Timestep file path property (no longer file-based)
 
     // Deprecated properties (SimMatlab/MatlabParam/WavePath/ReportPath/RDPath) removed from UI
 
@@ -8435,6 +8487,41 @@ void QtWorkspacePropertyManager::initializeProperty(QtProperty* property) {
     addDouble(tr("Range"), val.GetHomeViewpointRange(), d_ptr->m_properyToHomeRange, d_ptr->m_homeRangeToPropery,
               0.0, 1000000.0, 2, 10.0);
 
+    // Simulation Time group (English labels)
+    QtProperty* simGroup = d_ptr->m_groupProperyManager->addProperty();
+    simGroup->setPropertyName(tr("Simulation Time"));
+    d_ptr->m_properyToSimTimeGroup[property] = simGroup;
+    d_ptr->m_simTimeGroupToPropery[simGroup] = property;
+    property->addSubProperty(simGroup);
+
+    auto addSimDouble = [&](const QString& name, double init,
+                            QMap<const QtProperty*, QtProperty*>& propToChild,
+                            QMap<const QtProperty*, QtProperty*>& childToProp) {
+        QtProperty* dp = d_ptr->m_doubleProperyManager->addProperty();
+        dp->setPropertyName(name);
+        d_ptr->m_doubleProperyManager->setValueOnly(dp, init);
+        d_ptr->m_doubleProperyManager->setRange(dp, -1e12, 1e12);
+        d_ptr->m_doubleProperyManager->setDecimals(dp, 6);
+        d_ptr->m_doubleProperyManager->setSingleStep(dp, 0.1);
+        simGroup->addSubProperty(dp);
+        propToChild[property] = dp;
+        childToProp[dp] = property;
+    };
+    addSimDouble(tr("Simulation Start"), val.GetSimulationStart(), d_ptr->m_properyToSimStart, d_ptr->m_simStartToPropery);
+    addSimDouble(tr("Simulation End"), val.GetSimulationEnd(), d_ptr->m_properyToSimEnd, d_ptr->m_simEndToPropery);
+    // Simulation Step (playback speed multiplier)
+    {
+        QtProperty* dp = d_ptr->m_doubleProperyManager->addProperty();
+        dp->setPropertyName(tr("Simulation Step"));
+        d_ptr->m_doubleProperyManager->setValueOnly(dp, val.GetSimulationStep());
+        d_ptr->m_doubleProperyManager->setRange(dp, 0.25, 8.0);
+        d_ptr->m_doubleProperyManager->setDecimals(dp, 2);
+        d_ptr->m_doubleProperyManager->setSingleStep(dp, 0.25);
+        simGroup->addSubProperty(dp);
+        d_ptr->m_properyToSimStep[property] = dp;
+        d_ptr->m_simStepToPropery[dp] = property;
+    }
+
     // Add grouped file sections
 #if 0 // Hide resource groups (Curves/Surfaces/Tables/Lights/Polars/Images) in workspace property box
     auto addGroup = [&](FileEntryType type, const QString& groupName,
@@ -8523,12 +8610,7 @@ void QtWorkspacePropertyManager::uninitializeProperty(QtProperty* property) {
 	}
 	d_ptr->m_properyToDescription.remove(property);
 
-    prop = d_ptr->m_timestepToPropery[property];
-    if (prop) {
-        d_ptr->m_timestepToPropery.remove(prop);
-        delete prop;
-    }
-    d_ptr->m_properyToTimestep.remove(property);
+    // Removed: Timestep file path cleanup
 
     prop = d_ptr->m_simMatlabToPropery[property];
     if (prop) {
@@ -8597,6 +8679,26 @@ void QtWorkspacePropertyManager::uninitializeProperty(QtProperty* property) {
     }
     d_ptr->m_properyToHomeViewGroup.remove(property);
 
+    // Simulation Time cleanup
+    auto removeSimChild = [&](QMap<const QtProperty*, QtProperty*>& propToChild,
+                              QMap<const QtProperty*, QtProperty*>& childToProp) {
+        QtProperty* child = propToChild.value(property, nullptr);
+        if (child) {
+            childToProp.remove(child);
+            delete child;
+        }
+        propToChild.remove(property);
+    };
+    removeSimChild(d_ptr->m_properyToSimStart, d_ptr->m_simStartToPropery);
+    removeSimChild(d_ptr->m_properyToSimEnd, d_ptr->m_simEndToPropery);
+    removeSimChild(d_ptr->m_properyToSimStep, d_ptr->m_simStepToPropery);
+    QtProperty* simGroup = d_ptr->m_properyToSimTimeGroup.value(property, nullptr);
+    if (simGroup) {
+        d_ptr->m_simTimeGroupToPropery.remove(simGroup);
+        delete simGroup;
+    }
+    d_ptr->m_properyToSimTimeGroup.remove(property);
+
     // Cleanup grouped file properties
     auto cleanupGroup = [&](QMap<const QtProperty*, QtProperty*>& propToGroup,
                             QMap<const QtProperty*, QtProperty*>& groupToProp,
diff --git a/src/ui/PropertyBrowser/qtworkspaceattribute.cpp b/src/ui/PropertyBrowser/qtworkspaceattribute.cpp
index e133146f..7be4d3b4 100644
--- a/src/ui/PropertyBrowser/qtworkspaceattribute.cpp
+++ b/src/ui/PropertyBrowser/qtworkspaceattribute.cpp
@@ -62,35 +62,65 @@ const QString QWorkspaceAttribute::GetDescription() const {
 }
 
 
-void QWorkspaceAttribute::SetTimeStep(const QString& timestep) {
-    if (nullptr == workspace_) {
-        return;
-    }
+// 已移除：时间步长文件路径设置/获取（不再从文件读取）
 
-    Timestep* obj = workspace_->GetTimestep();
-    if (nullptr == obj) {
-        workspace_->SetTimestepPath(timestep);
-        return;
-    }
-
-    const QString& path = obj->GetPath();
-    if (path == timestep) {
-        return;
-    }
-
-    workspace_->SetTimestepPath(timestep);
+void QWorkspaceAttribute::SetSimulationStart(double start) {
+    if (!workspace_) return;
+    Timestep* t = workspace_->GetTimestep();
+    if (!t) return;
+    double minTime = 0.0, maxTime = 0.0, step = 0.0;
+    t->GetRange(minTime, maxTime, step);
+    t->SetManualRange(start, maxTime);
 }
 
-const QString QWorkspaceAttribute::GetTimeStep() const {
-    if (nullptr == workspace_) {
-        return "";
-    }
+double QWorkspaceAttribute::GetSimulationStart() const {
+    if (!workspace_) return 0.0;
+    Timestep* t = workspace_->GetTimestep();
+    if (!t) return 0.0;
+    double minTime = 0.0, maxTime = 0.0, step = 0.0;
+    t->GetRange(minTime, maxTime, step);
+    return minTime;
+}
 
-    Timestep* timestep = workspace_->GetTimestep();
-    if (nullptr == timestep) {
-        return "";
-    }
-    return timestep->GetPath();
+void QWorkspaceAttribute::SetSimulationEnd(double end) {
+    if (!workspace_) return;
+    Timestep* t = workspace_->GetTimestep();
+    if (!t) return;
+    double minTime = 0.0, maxTime = 0.0, step = 0.0;
+    t->GetRange(minTime, maxTime, step);
+    t->SetManualRange(minTime, end);
+}
+
+double QWorkspaceAttribute::GetSimulationEnd() const {
+    if (!workspace_) return 0.0;
+    Timestep* t = workspace_->GetTimestep();
+    if (!t) return 0.0;
+    double minTime = 0.0, maxTime = 0.0, step = 0.0;
+    t->GetRange(minTime, maxTime, step);
+    return maxTime;
+}
+
+void QWorkspaceAttribute::SetSimulationRange(double start, double end) {
+    if (!workspace_) return;
+    Timestep* t = workspace_->GetTimestep();
+    if (!t) return;
+    t->SetManualRange(start, end);
+}
+
+void QWorkspaceAttribute::SetSimulationStep(double step) {
+    if (!workspace_) return;
+    Timestep* t = workspace_->GetTimestep();
+    if (!t) return;
+    t->SetSpeed(step);
+}
+
+double QWorkspaceAttribute::GetSimulationStep() const {
+    if (!workspace_) return 1.0;
+    Timestep* t = workspace_->GetTimestep();
+    if (!t) return 1.0;
+    double minTime = 0.0, maxTime = 0.0, step = 0.0;
+    t->GetRange(minTime, maxTime, step);
+    return step;
 }
 
 // Deprecated workspace path setters/getters removed
diff --git a/src/ui/PropertyBrowser/qtworkspaceattribute.h b/src/ui/PropertyBrowser/qtworkspaceattribute.h
index 66d697f9..a97996e0 100644
--- a/src/ui/PropertyBrowser/qtworkspaceattribute.h
+++ b/src/ui/PropertyBrowser/qtworkspaceattribute.h
@@ -62,8 +62,17 @@ public:
     void SetDescription(const QString& desc);
     const QString GetDescription() const;
 
-    void SetTimeStep(const QString& timestep);
-    const QString GetTimeStep() const;
+    // 已移除：时间步长文件路径（不再从文件读取）
+
+    // Simulation time (manual range) for playback
+    void SetSimulationStart(double start);
+    double GetSimulationStart() const;
+    void SetSimulationEnd(double end);
+    double GetSimulationEnd() const;
+    void SetSimulationRange(double start, double end);
+    // Playback speed (step multiplier)
+    void SetSimulationStep(double step);
+    double GetSimulationStep() const;
 
     // Deprecated fields removed: SimMatlab/MatlabParam/WavePath/ReportPath/RDPath
 
diff --git a/src/utils/TransformPath.cpp b/src/utils/TransformPath.cpp
index 46cb4540..336cad0d 100644
--- a/src/utils/TransformPath.cpp
+++ b/src/utils/TransformPath.cpp
@@ -36,6 +36,8 @@ TransformPath* TransformPath::LoadFromFile(const QString& path, QObject* parent)
 
     std::vector<Transform> transforms;
 
+    std::vector<double> times;
+
     while (!in.atEnd()) {
         QString line = in.readLine();
         if (line.trimmed().isEmpty()) {
@@ -67,11 +69,14 @@ TransformPath* TransformPath::LoadFromFile(const QString& path, QObject* parent)
         transform.GetRotation().set(pitch, roll, heading);
 
         // 当前 PathComponent 使用 WorkSpace 的 Timestep 作为时间轴，这里暂不保存 time 字段
-        // 若未来需要按文件时间驱动，可扩展 TransformPath 结构以记录时间。
+        // 现在记录时间以支持按路径文件驱动回放
+        times.push_back(time);
 
         transforms.push_back(transform);
     }
     file.close();
 
-    return new TransformPath(std::move(transforms), parent);
+    TransformPath* tp = new TransformPath(std::move(transforms), parent);
+    tp->SetTimes(std::move(times));
+    return tp;
 }
diff --git a/src/utils/TransformPath.h b/src/utils/TransformPath.h
index 3084e812..90dc2d6d 100644
--- a/src/utils/TransformPath.h
+++ b/src/utils/TransformPath.h
@@ -21,6 +21,15 @@ public:
 		return transforms_;
 	}
 
+    const std::vector<double>& GetTimes() const {
+        return times_;
+    }
+
+    void SetTimes(std::vector<double> times) {
+        times_ = std::move(times);
+    }
+
 private:
 	std::vector<Transform> transforms_;
+    std::vector<double> times_;
 };
\ No newline at end of file
diff --git a/src/workspace/Timestep.cpp b/src/workspace/Timestep.cpp
index 9e135ecb..fff2408c 100644
--- a/src/workspace/Timestep.cpp
+++ b/src/workspace/Timestep.cpp
@@ -1,6 +1,8 @@
 #include "workspace/Timestep.h"
 
 #include <algorithm>
+#include <limits>
+#include <cmath>
 
 #include <QFile>
 #include <QTextStream>
@@ -10,51 +12,47 @@
 #include "common/RecourceHelper.h"
 #include "common/SpdLogger.h"
 
-Timestep::Timestep(const std::vector<double>& steps, const QString& path, WorkSpace* parent /*= nullptr*/) noexcept
+Timestep::Timestep(WorkSpace* parent /*= nullptr*/) noexcept
     : QObject((QObject*)parent)
-    , steps_(steps)
-    , path_(path)
     , workSpace_(parent) {
-    maxTime_ = *steps_.rbegin();
+    // 默认最大时间为 0，由数据或手动区间设置
     // 初始化为 1.0x，如果列表中没有 1.0，则取最接近中间的默认索引
     auto it = std::find(speedLevels_.begin(), speedLevels_.end(), 1.0);
     speedIndex_ = it != speedLevels_.end() ? int(std::distance(speedLevels_.begin(), it)) : speedIndex_;
     currentStep_ = speedLevels_[speedIndex_];
 }
 
-Timestep* Timestep::Load(const QString& path, WorkSpace* workSpace) {
-    const QString filePath = QString("%1/%2").arg(workSpace->GetDir()).arg(path);
-    LOG_INFO("Load timestep: {}", filePath.toStdString());
+void Timestep::SetManualRange(double start, double end) {
+    hasManualRange_ = true;
+    manualStart_ = start;
+    manualEnd_ = end;
+    // 当设置手动区间时，更新最大时间使播放边界正确
+    maxTime_ = end;
+    // 通知 UI 更新范围与步进
+    double minTime = 0.0, maxTime = 0.0, step = 0.0;
+    GetRange(minTime, maxTime, step);
+    emit RangeChanged(minTime, maxTime, step);
+}
 
-    QFile file(filePath);
-    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
-        LOG_WARN("Cannot open file for reading: {}", file.errorString().toLocal8Bit().constData());
-        return nullptr;
-    }
-
-    QTextStream in(&file);
-    std::vector<double> numbers;
-
-    while (!in.atEnd()) {
-        QString line = in.readLine();
-        bool ok;
-        double value = line.toDouble(&ok);
-        if (ok) {
-            numbers.push_back(value); 
-        } else {
-            LOG_WARN("Cannot open file for reading: {}", line.toStdString());
-        }
-    }
-
-    file.close();
-
-    Timestep* timestep = new Timestep(numbers, path, workSpace);
-    return timestep;
+void Timestep::ClearManualRange() {
+    hasManualRange_ = false;
+    manualStart_ = 0.0;
+    manualEnd_ = 0.0;
+    // 恢复为数据驱动的最大时间，保留当前 maxTime_
+    // 通知 UI 更新范围与步进
+    double minTime = 0.0, maxTime = 0.0, step = 0.0;
+    GetRange(minTime, maxTime, step);
+    emit RangeChanged(minTime, maxTime, step);
 }
 
 void Timestep::GetRange(double& minTime, double& maxTime, double& step) {
-    minTime = *steps_.begin();
-    maxTime = maxTime_;
+    if (hasManualRange_) {
+        minTime = manualStart_;
+        maxTime = manualEnd_;
+    } else {
+        minTime = 0.0;
+        maxTime = maxTime_;
+    }
     step = currentStep_;
 }
 
@@ -90,7 +88,7 @@ bool Timestep::IsStoped() {
 void Timestep::Start() {
     LOG_INFO("enter");
     playStatus_ = PlayStatus::PS_Started;
-    current_ = 0.0;
+    current_ = hasManualRange_ ? manualStart_ : 0.0;
 
     if (nullptr == workSpace_) {
         LOG_WARN("workSpace_ is nullptr");
@@ -127,7 +125,7 @@ void Timestep::Pause() {
 
 void Timestep::Stop() {
     LOG_INFO("enter");
-    current_ = maxTime_;
+    current_ = hasManualRange_ ? manualEnd_ : maxTime_;
     playStatus_ = PlayStatus::PS_Stoped;
     if (nullptr == workSpace_) {
         LOG_WARN("workSpace_ is nullptr");
@@ -151,6 +149,13 @@ void Timestep::Up() {
     emit StepChanged(currentStep_);
 }
 
+void Timestep::SetDataMaxTime(double end) {
+    maxTime_ = end;
+    double minTime = 0.0, maxTime = 0.0, step = 0.0;
+    GetRange(minTime, maxTime, step);
+    emit RangeChanged(minTime, maxTime, step);
+}
+
 void Timestep::Down() {
     // 降到上一个倍率（保底）
     if (speedIndex_ > 0) {
@@ -159,3 +164,21 @@ void Timestep::Down() {
     currentStep_ = speedLevels_[speedIndex_];
     emit StepChanged(currentStep_);
 }
+
+void Timestep::SetSpeed(double speed) {
+    if (speedLevels_.empty()) {
+        return;
+    }
+    int bestIdx = 0;
+    double bestDiff = std::numeric_limits<double>::max();
+    for (int i = 0; i < static_cast<int>(speedLevels_.size()); ++i) {
+        double diff = std::fabs(speedLevels_[i] - speed);
+        if (diff < bestDiff) {
+            bestDiff = diff;
+            bestIdx = i;
+        }
+    }
+    speedIndex_ = bestIdx;
+    currentStep_ = speedLevels_[speedIndex_];
+    emit StepChanged(currentStep_);
+}
diff --git a/src/workspace/Timestep.h b/src/workspace/Timestep.h
index 1e85fa8d..31e680ff 100644
--- a/src/workspace/Timestep.h
+++ b/src/workspace/Timestep.h
@@ -8,7 +8,7 @@
 class WorkSpace;
 
 class Timestep : public QObject {
-	Q_OBJECT
+    Q_OBJECT
 public:
     enum class PlayStatus : uint8_t {
         PS_Started,
@@ -17,23 +17,14 @@ public:
     };
 
 public:
-	explicit Timestep(const std::vector<double>& steps, const QString& path, WorkSpace* parent = nullptr) noexcept;
+	explicit Timestep(WorkSpace* parent = nullptr) noexcept;
 	~Timestep() override = default;
 
-	static Timestep* Load(const QString& path, WorkSpace* workSpace = nullptr);
-
-	const std::vector<double>& GetSteps() const {
-		return steps_;
-	}
-	const QString& GetPath() const {
-		return path_;
-	}
-
-	void GetRange(double& minTime, double& maxTime, double& step);
-	void Update(double dt);
-	double GetCurrent() const {
-		return current_;
-	}
+    void GetRange(double& minTime, double& maxTime, double& step);
+    void Update(double dt);
+    double GetCurrent() const {
+        return current_;
+    }
 
 	bool IsPause();
 	bool IsStoped();
@@ -42,22 +33,34 @@ public:
 	void Pause();
 	void Stop();
 
-	void Up();
+    void Up();
     void Down();
+    // 设置播放速度（倍率），会选取最接近的预设倍率并触发 StepChanged
+    void SetSpeed(double speed);
+
+    // 设置数据驱动的默认最大时间（非手动区间），用于没有文件步长时的播放边界
+    void SetDataMaxTime(double end);
 
 	WorkSpace* GetWorkSpace() const {
 		return workSpace_;
 	}
 
+    // 手动时间区间（可选）：允许用户指定起止时间，替代或重映射步骤
+    void SetManualRange(double start, double end);
+    void ClearManualRange();
+    bool HasManualRange() const { return hasManualRange_; }
+    double GetManualStart() const { return manualStart_; }
+    double GetManualEnd() const { return manualEnd_; }
+
 Q_SIGNALS:
-	void StatusChanged(int);
-	void StepChanged(double);
-	void TimeChanged(double);
+    void StatusChanged(int);
+    void StepChanged(double);
+    void TimeChanged(double);
+    // 当时间范围或步进倍率更新时通知 UI（例如设置手动区间或清除）
+    void RangeChanged(double minTime, double maxTime, double step);
 	
 
 private:
-    std::vector<double> steps_;
-    QString path_;
     double current_{ 0.0 };
     double maxTime_{ 0.0 };
     // 播放速度（倍率），与 UI 显示一致，比如 0.5x、1x、2x
@@ -66,8 +69,12 @@ private:
     std::vector<double> speedLevels_{ 0.25, 0.5, 1.0, 2.0, 4.0, 8.0 };
     int speedIndex_{ 2 }; // 默认指向 1.0x
 
-	
-    PlayStatus playStatus_{ PlayStatus::PS_Stoped };
-    WorkSpace* workSpace_{ nullptr };
+
+	PlayStatus playStatus_{ PlayStatus::PS_Stoped };
+	WorkSpace* workSpace_{ nullptr };
+
+    bool hasManualRange_{ false };
+    double manualStart_{ 0.0 };
+    double manualEnd_{ 0.0 };
 };
 
diff --git a/src/workspace/WorkSpace.cpp b/src/workspace/WorkSpace.cpp
index d6497053..b3088522 100644
--- a/src/workspace/WorkSpace.cpp
+++ b/src/workspace/WorkSpace.cpp
@@ -263,24 +263,11 @@ void WorkSpace::SetActiveScene(OEScene* scene) {
     //homeViewpoint_ = vp;
 }
 
-bool WorkSpace::SetTimestep(Timestep* timestep) {
-    if (!timestep) {
-        return false;
+void WorkSpace::EnsureTimestep() {
+    if (nullptr == timestep_) {
+        timestep_ = new Timestep(this);
+        emit TimestepChanged(timestep_);
     }
-
-    if (nullptr != timestep_ && timestep_ != timestep) {
-        timestep_->deleteLater();
-    }
-
-    timestep_ = timestep;
-    emit TimestepChanged(timestep_);
-    return true;
-}
-
-bool WorkSpace::SetTimestepPath(const QString& path) {
-    Timestep* timestep = Timestep::Load(path, this);
-
-    return SetTimestep(timestep);
 }
 
 bool WorkSpace::SetLampStatus(class LampStatus* lampStatus) {
@@ -368,9 +355,7 @@ void WorkSpace::OnLoaded() {
     if (nullptr != lampStatus_) {
         emit LampStatusChanged(lampStatus_);
     }
-    if (nullptr != timestep_) {
-        emit TimestepChanged(timestep_);
-    }
+    EnsureTimestep();
     // Execute commands configured for onLoad
     ExecuteCommands(CommandWhen::OnLoad);
 }
diff --git a/src/workspace/WorkSpace.h b/src/workspace/WorkSpace.h
index e5d3444d..48c95e01 100644
--- a/src/workspace/WorkSpace.h
+++ b/src/workspace/WorkSpace.h
@@ -1,4 +1,4 @@
-#pragma once
+#pragma once
 
 #include <map>
 #include <memory>
@@ -100,8 +100,7 @@ public:
 		dyt_check(nullptr != scene_);
 		return scene_;
 	}
-	bool SetTimestep(class Timestep* timestep);
-	bool SetTimestepPath(const QString& path);
+    // Timestep lifecycle is managed internally; external setting removed
     class Timestep* GetTimestep() const {
 		return timestep_;
     }
@@ -132,8 +131,9 @@ public:
 
     void OnLoaded();
 
-    // 通知：某类型的文件条目属性已更新（不改变数量，仅触发刷新）
     void NotifyFileEntryUpdated(FileEntryType type, std::shared_ptr<FileEntry> fileEntry = nullptr);
+        // Ensure a timestep exists; create if missing and emit change
+    void EnsureTimestep();
 
 Q_SIGNALS:
     void EntityAdded(class Entity* entity);
@@ -171,3 +171,5 @@ public:
 	friend class WorkSpaceXMLParse;
 };
 
+
+
diff --git a/src/workspace/WorkSpaceXMLParse.cpp b/src/workspace/WorkSpaceXMLParse.cpp
index 207fb69e..c5b27ad2 100644
--- a/src/workspace/WorkSpaceXMLParse.cpp
+++ b/src/workspace/WorkSpaceXMLParse.cpp
@@ -2,6 +2,7 @@
 
 #include "workspace/WorkSpace.h"
 #include "entities/EntitiesManager.h"
+#include "workspace/Timestep.h"
 
 #include "common/SpdLogger.h"
 #include "workspace/WorkSpaceManager.h"
@@ -59,14 +60,35 @@ bool WorkSpaceXMLParse::ParseTimestep(const tinyxml2::XMLElement* element) {
         LOG_WARN("element is nullptr");
         return false;
     }
-
-    const char* path = element->Attribute("path");
-    if (nullptr == path) {
-        LOG_WARN("element not has path");
+    // 确保存在 Timestep 实例
+    workSpace_->EnsureTimestep();
+    Timestep* t = workSpace_->GetTimestep();
+    if (!t) {
         return false;
     }
-    
-    return workSpace_->SetTimestepPath(path);
+
+    // 解析属性：manual(0/1)、start、end、step
+    int manualFlag = 0;
+    element->QueryIntAttribute("manual", &manualFlag);
+    double start = 0.0;
+    double end = 0.0;
+    double step = 0.0;
+    bool hasStart = (element->QueryDoubleAttribute("start", &start) == tinyxml2::XML_SUCCESS);
+    bool hasEnd = (element->QueryDoubleAttribute("end", &end) == tinyxml2::XML_SUCCESS);
+    bool hasStep = (element->QueryDoubleAttribute("step", &step) == tinyxml2::XML_SUCCESS);
+
+    if (hasStep) {
+        t->SetSpeed(step);
+    }
+
+    // 若标记为手动或具有完整的 start/end，则设置手动范围；否则按数据最大时间设置边界
+    if (manualFlag != 0 || (hasStart && hasEnd)) {
+        t->SetManualRange(hasStart ? start : 0.0, hasEnd ? end : 0.0);
+    } else if (hasEnd) {
+        t->SetDataMaxTime(end);
+    }
+
+    return true;
 }
 
 bool WorkSpaceXMLParse::ParseLamp(const tinyxml2::XMLElement* element) {
diff --git a/src/workspace/WorkSpaceXMLWrite.cpp b/src/workspace/WorkSpaceXMLWrite.cpp
index 1a6170fa..17c754db 100644
--- a/src/workspace/WorkSpaceXMLWrite.cpp
+++ b/src/workspace/WorkSpaceXMLWrite.cpp
@@ -34,9 +34,9 @@ bool WorkSpaceXMLWrite::Save(const QString& path) {
     }
 
     doc.LinkEndChild(scene);
+    SaveTimeStep(scene);
 
     SaveChart(scene, &doc);
-    SaveTimeStep(scene);
 	SaveLamp(scene);
     SaveCommond(scene);
     SaveFiles(scene, &doc);
@@ -66,13 +66,31 @@ bool WorkSpaceXMLWrite::SaveScene(tinyxml2::XMLElement* scene) {
     return true;
 }
 
+// Removed: SaveTimeStep — timestep is no longer file-based
+// 新增：保存 Timestep 的手动范围与步长倍率
 bool WorkSpaceXMLWrite::SaveTimeStep(tinyxml2::XMLElement* scene) {
-    Timestep* timestep = workSpace_->GetTimestep();
-    if (nullptr == timestep) {
+    if (nullptr == workSpace_) {
         return false;
     }
-    tinyxml2::XMLElement* timestepXml = scene->InsertNewChildElement("timestep");
-    timestepXml->SetAttribute("path", timestep->GetPath().toStdString().c_str());
+    auto* t = workSpace_->GetTimestep();
+    if (!t) {
+        // 若尚未创建，确保存在一个默认实例，以保证文件的一致性
+        workSpace_->EnsureTimestep();
+        t = workSpace_->GetTimestep();
+    }
+    if (!t) {
+        return false;
+    }
+
+    double start = 0.0, end = 0.0, step = 1.0;
+    t->GetRange(start, end, step);
+
+    tinyxml2::XMLElement* timestep = scene->InsertNewChildElement("timestep");
+    timestep->SetAttribute("manual", t->HasManualRange() ? 1 : 0);
+    timestep->SetAttribute("start", start);
+    timestep->SetAttribute("end", end);
+    timestep->SetAttribute("step", step);
+
     return true;
 }