diff --git a/docs/util/detail/demo.md b/docs/util/detail/demo.md
index 12e9ff05..24e20589 100644
--- a/docs/util/detail/demo.md
+++ b/docs/util/detail/demo.md
@@ -1,4 +1,4 @@
-<pre class="layui-code" lay-options="{preview: true, codeStyle: 'height: 535px;', layout: ['preview', 'code'], tools: ['full']}">
+<pre class="layui-code" lay-options="{preview: 'iframe', codeStyle: 'height: 535px;', layout: ['preview', 'code'], tools: ['full']}">
   <textarea>
 <h3 class="ws-anchor ws-bold">倒计时</h3>
 
@@ -125,4 +125,4 @@ layui.use(function(){
 });
 </script>
   </textarea>
-</pre>
\ No newline at end of file
+</pre>