diff --git a/packages/element/src/form-dialog/index.ts b/packages/element/src/form-dialog/index.ts
index 13d104b2471..49f37254ac9 100644
--- a/packages/element/src/form-dialog/index.ts
+++ b/packages/element/src/form-dialog/index.ts
@@ -308,6 +308,7 @@ export function FormDialog(
         parent: getProtalContext(id as string | symbol),
       })
       env.instance.$mount(env.root)
+      env.root = env.instance.$el
     }
 
     env.instance.visible = visible