diff --git a/simple-mind-map/src/constants/defaultOptions.js b/simple-mind-map/src/constants/defaultOptions.js
index 886b914d..71510f26 100644
--- a/simple-mind-map/src/constants/defaultOptions.js
+++ b/simple-mind-map/src/constants/defaultOptions.js
@@ -67,9 +67,7 @@ export const defaultOpt = {
     close: ''
   },
   // 处理收起节点数量
-  expandBtnNumHandler: num => {
-    return num
-  },
+  expandBtnNumHandler: null,
   // 是否显示带数量的收起按钮
   isShowExpandNum: true,
   // 是否只有当鼠标在画布内才响应快捷键事件
diff --git a/simple-mind-map/src/core/render/node/nodeExpandBtn.js b/simple-mind-map/src/core/render/node/nodeExpandBtn.js
index 87941fde..baf26b36 100644
--- a/simple-mind-map/src/core/render/node/nodeExpandBtn.js
+++ b/simple-mind-map/src/core/render/node/nodeExpandBtn.js
@@ -1,5 +1,6 @@
 import btnsSvg from '../../../svg/btns'
 import { SVG, Circle, G, Text } from '@svgdotjs/svg.js'
+import { isUndef } from '../../../utils'
 
 // 创建展开收起按钮的内容节点
 function createExpandNodeContent() {
@@ -78,7 +79,12 @@ function updateExpandBtnNode() {
         })
         // 计算子节点数量
         let count = this.sumNode(this.nodeData.children)
-        count = expandBtnNumHandler(count)
+        if (typeof expandBtnNumHandler === 'function') {
+          const res = expandBtnNumHandler(count, this)
+          if (!isUndef(res)) {
+            count = res
+          }
+        }
         node.text(String(count))
       } else {
         this._fillExpandNode.stroke('none')