diff --git a/AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs b/AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs
index 9f7305d..83070b6 100644
--- a/AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs
+++ b/AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs
@@ -443,9 +443,12 @@ namespace AIStudio.Wpf.DiagramDesigner
 
         public virtual async Task AfterExecute()
         {
-            IsExecuting = false;
-            if (Next != null)
-                await Next.Execute();
+            if (IsExecuting)
+            {
+                IsExecuting = false;
+                if (Next != null)
+                    await Next.Execute();
+            }
         }
 
         public virtual object GetResult()