diff --git a/simple-mind-map/src/Node.js b/simple-mind-map/src/Node.js
index 117fc6c2..d00867a3 100644
--- a/simple-mind-map/src/Node.js
+++ b/simple-mind-map/src/Node.js
@@ -990,6 +990,7 @@ class Node {
      * @Desc: 创建或更新展开收缩按钮内容 
      */
     updateExpandBtnNode() {
+        if (this.children.length === 0) return
         if (this._expandBtn) {
             this._expandBtn.clear()
         }
diff --git a/web/package.json b/web/package.json
index 1315a3b5..9279d3b2 100644
--- a/web/package.json
+++ b/web/package.json
@@ -12,6 +12,7 @@
     "@toast-ui/editor": "^3.1.5",
     "core-js": "^3.6.5",
     "element-ui": "^2.15.1",
+    "simple-mind-map": "^0.2.3",
     "vue": "^2.6.11",
     "vue-router": "^3.5.1",
     "vuex": "^3.6.2"