diff --git a/GFramework.Core.Tests/Coroutine/CoroutineSchedulerAdvancedTests.cs b/GFramework.Core.Tests/Coroutine/CoroutineSchedulerAdvancedTests.cs
index 0087b351..f262cd55 100644
--- a/GFramework.Core.Tests/Coroutine/CoroutineSchedulerAdvancedTests.cs
+++ b/GFramework.Core.Tests/Coroutine/CoroutineSchedulerAdvancedTests.cs
@@ -171,4 +171,63 @@ public sealed class CoroutineSchedulerAdvancedTests
 
         Assert.That(status, Is.EqualTo(CoroutineCompletionStatus.Faulted));
     }
+
+    /// <summary>
+    ///     验证完成状态缓存有固定上限，避免无限增长。
+    /// </summary>
+    [Test]
+    public void CompletionStatusHistory_Should_Be_Bounded()
+    {
+        var timeSource = new FakeTimeSource();
+        var scheduler = new CoroutineScheduler(timeSource);
+        var handles = new List<CoroutineHandle>();
+
+        IEnumerator<IYieldInstruction> ImmediateCoroutine()
+        {
+            yield break;
+        }
+
+        for (var i = 0; i < 1100; i++)
+        {
+            handles.Add(scheduler.Run(ImmediateCoroutine()));
+        }
+
+        Assert.That(scheduler.TryGetCompletionStatus(handles[0], out _), Is.False);
+        Assert.That(scheduler.TryGetCompletionStatus(handles[^1], out var latestStatus), Is.True);
+        Assert.That(latestStatus, Is.EqualTo(CoroutineCompletionStatus.Completed));
+    }
+
+    /// <summary>
+    ///     验证作为首个等待指令的 WaitForCoroutine 会立即启动子协程，并沿用父协程取消令牌。
+    /// </summary>
+    [Test]
+    public async Task WaitForCoroutine_Should_Start_Child_During_Prewarm_And_Propagate_Cancellation()
+    {
+        var timeSource = new FakeTimeSource();
+        var scheduler = new CoroutineScheduler(timeSource);
+        using var cancellationTokenSource = new CancellationTokenSource();
+
+        IEnumerator<IYieldInstruction> ChildCoroutine()
+        {
+            yield return new Delay(10);
+        }
+
+        IEnumerator<IYieldInstruction> ParentCoroutine()
+        {
+            yield return new WaitForCoroutine(ChildCoroutine());
+        }
+
+        var handle = scheduler.Run(ParentCoroutine(), cancellationToken: cancellationTokenSource.Token);
+
+        Assert.That(scheduler.ActiveCoroutineCount, Is.EqualTo(2));
+
+        cancellationTokenSource.Cancel();
+        timeSource.Advance(0.1);
+        scheduler.Update();
+
+        var status = await scheduler.WaitForCompletionAsync(handle);
+
+        Assert.That(status, Is.EqualTo(CoroutineCompletionStatus.Cancelled));
+        Assert.That(scheduler.ActiveCoroutineCount, Is.EqualTo(0));
+    }
 }
\ No newline at end of file
diff --git a/GFramework.Core/Coroutine/CoroutineScheduler.cs b/GFramework.Core/Coroutine/CoroutineScheduler.cs
index b11a5e57..0a24ce6d 100644
--- a/GFramework.Core/Coroutine/CoroutineScheduler.cs
+++ b/GFramework.Core/Coroutine/CoroutineScheduler.cs
@@ -34,10 +34,13 @@ public sealed class CoroutineScheduler(
     ITimeSource? realtimeTimeSource = null,
     CoroutineExecutionStage executionStage = CoroutineExecutionStage.Update)
 {
+    private const int CompletionStatusHistoryLimit = 1024;
+
     private readonly Dictionary<CoroutineHandle, TaskCompletionSource<CoroutineCompletionStatus>> _completionSources =
         new();
 
     private readonly Dictionary<CoroutineHandle, CoroutineCompletionStatus> _completionStatuses = new();
+    private readonly Queue<CoroutineHandle> _completionStatusOrder = new();
     private readonly Dictionary<string, HashSet<CoroutineHandle>> _grouped = new();
     private readonly ILogger _logger = LoggerFactoryResolver.Provider.CreateLogger(nameof(CoroutineScheduler));
     private readonly Dictionary<CoroutineHandle, CoroutineMetadata> _metadata = new();
@@ -218,6 +221,7 @@ public sealed class CoroutineScheduler(
 
         var slot = new CoroutineSlot
         {
+            CancellationToken = cancellationToken,
             Enumerator = coroutine,
             State = CoroutineState.Running,
             Handle = handle,
@@ -386,7 +390,14 @@ public sealed class CoroutineScheduler(
         {
             case WaitForCoroutine waitForCoroutine:
             {
-                var targetHandle = Run(waitForCoroutine.Coroutine);
+                var targetHandle = Run(waitForCoroutine.Coroutine, cancellationToken: slot.CancellationToken);
+                if (!targetHandle.IsValid)
+                {
+                    waitForCoroutine.Complete();
+                    slot.Waiting = null;
+                    break;
+                }
+
                 slot.Waiting = waitForCoroutine;
                 WaitForCoroutine(slot.Handle, targetHandle);
                 break;
@@ -596,6 +607,8 @@ public sealed class CoroutineScheduler(
         _tagged.Clear();
         _grouped.Clear();
         _waiting.Clear();
+        _completionStatuses.Clear();
+        _completionStatusOrder.Clear();
 
         _nextSlot = 0;
         ActiveCoroutineCount = 0;
@@ -629,7 +642,7 @@ public sealed class CoroutineScheduler(
             }
             else
             {
-                slot.Waiting = slot.Enumerator.Current;
+                HandleYieldInstruction(slot, slot.Enumerator.Current);
             }
         }
         catch (Exception ex)
@@ -712,7 +725,7 @@ public sealed class CoroutineScheduler(
             source.TrySetResult(completionStatus);
         }
 
-        _completionStatuses[handle] = completionStatus;
+        RecordCompletionStatus(handle, completionStatus);
         OnCoroutineFinished?.Invoke(handle, completionStatus, exception);
     }
 
@@ -892,6 +905,23 @@ public sealed class CoroutineScheduler(
         _statistics.PausedCount = _pausedCount;
     }
 
+    /// <summary>
+    ///     记录协程最终状态，并对历史缓存施加固定上限，避免完成状态字典无限增长。
+    /// </summary>
+    /// <param name="handle">已结束的协程句柄。</param>
+    /// <param name="completionStatus">协程最终状态。</param>
+    private void RecordCompletionStatus(CoroutineHandle handle, CoroutineCompletionStatus completionStatus)
+    {
+        _completionStatuses[handle] = completionStatus;
+        _completionStatusOrder.Enqueue(handle);
+
+        while (_completionStatusOrder.Count > CompletionStatusHistoryLimit)
+        {
+            var expiredHandle = _completionStatusOrder.Dequeue();
+            _completionStatuses.Remove(expiredHandle);
+        }
+    }
+
     /// <summary>
     ///     为协程添加标签。
     /// </summary>
diff --git a/GFramework.Core/Coroutine/CoroutineSlot.cs b/GFramework.Core/Coroutine/CoroutineSlot.cs
index e4478037..1fb11994 100644
--- a/GFramework.Core/Coroutine/CoroutineSlot.cs
+++ b/GFramework.Core/Coroutine/CoroutineSlot.cs
@@ -13,6 +13,12 @@ internal sealed class CoroutineSlot
     /// </summary>
     public CancellationTokenRegistration CancellationRegistration;
 
+    /// <summary>
+    ///     创建该协程时传入的取消令牌。
+    ///     当协程启动子协程时，会把同一个取消令牌继续传递下去，以保持父子协程的取消语义一致。
+    /// </summary>
+    public CancellationToken CancellationToken;
+
     /// <summary>
     ///     协程枚举器，包含协程的执行逻辑
     /// </summary>
diff --git a/GFramework.Godot.Tests/Coroutine/GodotTimeSourceTests.cs b/GFramework.Godot.Tests/Coroutine/GodotTimeSourceTests.cs
index f1527dac..3f46fb1b 100644
--- a/GFramework.Godot.Tests/Coroutine/GodotTimeSourceTests.cs
+++ b/GFramework.Godot.Tests/Coroutine/GodotTimeSourceTests.cs
@@ -1,6 +1,5 @@
 using System.Collections.Generic;
 using GFramework.Godot.Coroutine;
-using NUnit.Framework;
 
 namespace GFramework.Godot.Tests.Coroutine;
 
@@ -49,4 +48,25 @@ public sealed class GodotTimeSourceTests
         Assert.That(timeSource.DeltaTime, Is.EqualTo(0.75).Within(0.0001));
         Assert.That(timeSource.CurrentTime, Is.EqualTo(2.0).Within(0.0001));
     }
+
+    /// <summary>
+    ///     验证绝对时间源在回拨时仍保持单调，不会把 CurrentTime 拉回去。
+    /// </summary>
+    [Test]
+    public void Update_Should_Keep_Absolute_Time_Monotonic_When_Provider_Goes_Backwards()
+    {
+        var values = new Queue<double>([5.0, 4.0, 6.5]);
+        var timeSource = new GodotTimeSource(() => values.Dequeue(), useAbsoluteTime: true);
+
+        timeSource.Update();
+        timeSource.Update();
+
+        Assert.That(timeSource.DeltaTime, Is.EqualTo(0).Within(0.0001));
+        Assert.That(timeSource.CurrentTime, Is.EqualTo(5.0).Within(0.0001));
+
+        timeSource.Update();
+
+        Assert.That(timeSource.DeltaTime, Is.EqualTo(1.5).Within(0.0001));
+        Assert.That(timeSource.CurrentTime, Is.EqualTo(6.5).Within(0.0001));
+    }
 }
\ No newline at end of file
diff --git a/GFramework.Godot/Coroutine/GodotTimeSource.cs b/GFramework.Godot/Coroutine/GodotTimeSource.cs
index ffdd3ae4..06cd5cbd 100644
--- a/GFramework.Godot/Coroutine/GodotTimeSource.cs
+++ b/GFramework.Godot/Coroutine/GodotTimeSource.cs
@@ -1,5 +1,4 @@
 using GFramework.Core.Abstractions.Coroutine;
-using Godot;
 
 namespace GFramework.Godot.Coroutine;
 
@@ -47,9 +46,11 @@ public sealed class GodotTimeSource(Func<double> timeProvider, bool useAbsoluteT
                 return;
             }
 
-            DeltaTime = Math.Max(0, value - _lastAbsoluteTime);
-            _lastAbsoluteTime = value;
-            CurrentTime = value;
+            // 对绝对时间源做单调钳制，避免 provider 回拨后把 CurrentTime 也拉回去。
+            var nextTime = Math.Max(value, _lastAbsoluteTime);
+            DeltaTime = nextTime - _lastAbsoluteTime;
+            _lastAbsoluteTime = nextTime;
+            CurrentTime = nextTime;
             return;
         }
 
diff --git a/GFramework.Godot/Coroutine/Timing.cs b/GFramework.Godot/Coroutine/Timing.cs
index 983fdc6f..774bfcc1 100644
--- a/GFramework.Godot/Coroutine/Timing.cs
+++ b/GFramework.Godot/Coroutine/Timing.cs
@@ -1,9 +1,5 @@
 using System.Reflection;
 using GFramework.Core.Abstractions.Coroutine;
-using GFramework.Core.Coroutine;
-using GFramework.Core.Coroutine.Instructions;
-using GFramework.Godot.Extensions;
-using Godot;
 
 namespace GFramework.Godot.Coroutine;
 
@@ -470,6 +466,11 @@ public partial class Timing : Node
             return handle;
         }
 
+        if (!GetScheduler(segment).IsCoroutineAlive(handle))
+        {
+            return handle;
+        }
+
         RegisterOwnedCoroutine(owner, handle);
         return handle;
     }
@@ -515,7 +516,13 @@ public partial class Timing : Node
     /// <returns>被终止的协程数量。</returns>
     public static int KillCoroutines(Node owner)
     {
-        return Instance.KillOwnedCoroutinesOnInstance(owner);
+        var count = 0;
+        foreach (var timing in EnumerateActiveInstances())
+        {
+            count += timing.KillOwnedCoroutinesOnInstance(owner);
+        }
+
+        return count;
     }
 
     /// <summary>
@@ -562,7 +569,13 @@ public partial class Timing : Node
     /// <returns>该节点当前归属的活跃协程数量。</returns>
     public static int GetOwnedCoroutineCount(Node owner)
     {
-        return Instance.GetOwnedCoroutineCountOnInstance(owner);
+        var count = 0;
+        foreach (var timing in EnumerateActiveInstances())
+        {
+            count += timing.GetOwnedCoroutineCountOnInstance(owner);
+        }
+
+        return count;
     }
 
     /// <summary>
@@ -683,6 +696,15 @@ public partial class Timing : Node
         return id < ActiveInstances.Length ? ActiveInstances[id] : null;
     }
 
+    /// <summary>
+    ///     枚举所有当前已注册的 Timing 实例。
+    /// </summary>
+    /// <returns>活跃 Timing 实例序列。</returns>
+    private static IEnumerable<Timing> EnumerateActiveInstances()
+    {
+        return ActiveInstances.Where(static timing => timing is not null).Select(static timing => timing!);
+    }
+
     /// <summary>
     ///     检查节点是否处于有效状态。
     /// </summary>