diff --git a/components/ChatInputBox/ChatInputBox.tsx b/components/ChatInputBox/ChatInputBox.tsx
index acd7d94..f79f976 100644
--- a/components/ChatInputBox/ChatInputBox.tsx
+++ b/components/ChatInputBox/ChatInputBox.tsx
@@ -162,6 +162,20 @@ export function ChatInputBox({ noData }: { noData: boolean }) {
       ...prev,
       [key]: value,
     }));
+    if (key === 'videoDuration') {
+      // 当选择 8s 时，强制关闭剧本扩展并禁用开关
+      if (value === '8s') {
+        setConfigOptions((prev) => ({
+          ...prev,
+          expansion_mode: false,
+        }));
+      } else {
+        setConfigOptions((prev) => ({
+          ...prev,
+          expansion_mode: true,
+        }));
+      }
+    }
   };
 
   const handleCreateVideo = async () => {
@@ -404,6 +418,7 @@ export function ChatInputBox({ noData }: { noData: boolean }) {
                         <Switch
                           size="small"
                           checked={configOptions.expansion_mode}
+                          disabled={configOptions.videoDuration === '8s'}
                           onChange={(checked) => onConfigChange('expansion_mode', checked)}
                         />
                       </div>