diff --git a/components/dropdown/demo/sub-menu.md b/components/dropdown/demo/sub-menu.md
index f54a9e952a..35dafc443d 100644
--- a/components/dropdown/demo/sub-menu.md
+++ b/components/dropdown/demo/sub-menu.md
@@ -21,8 +21,10 @@ const { SubMenu } = Menu;
const menu = (