diff --git a/examples/docs/en-US/menu.md b/examples/docs/en-US/menu.md
index 46f6807be..29d8d6021 100644
--- a/examples/docs/en-US/menu.md
+++ b/examples/docs/en-US/menu.md
@@ -34,7 +34,7 @@
       return {
         activeIndex: '1',
         activeIndex2: '1',
-        isCollapse: false
+        isCollapse: true
       };
     },
     methods: {
@@ -219,11 +219,18 @@ Vertical NavMenu could be collapsed.
   </el-menu-item>
 </el-menu>
 
+<style>
+  .el-menu-vertical-demo:not(.el-menu--collapse) {
+    width: 200px;
+    min-height: 400px;
+  }
+</style>
+
 <script>
   export default {
     data() {
       return {
-        isCollapse: false
+        isCollapse: true
       };
     },
     methods: {
diff --git a/examples/docs/zh-CN/menu.md b/examples/docs/zh-CN/menu.md
index 86697b689..1e162844a 100644
--- a/examples/docs/zh-CN/menu.md
+++ b/examples/docs/zh-CN/menu.md
@@ -219,11 +219,18 @@
   </el-menu-item>
 </el-menu>
 
+<style>
+  .el-menu-vertical-demo:not(.el-menu--collapse) {
+    width: 200px;
+    min-height: 400px;
+  }
+</style>
+
 <script>
   export default {
     data() {
       return {
-        isCollapse: false
+        isCollapse: true
       };
     },
     methods: {
diff --git a/packages/cascader/src/menu.vue b/packages/cascader/src/menu.vue
index 8f14be897..2341f0b10 100644
--- a/packages/cascader/src/menu.vue
+++ b/packages/cascader/src/menu.vue
@@ -81,7 +81,7 @@
         } else {
           this.activeValue = [item.value];
         }
-        this.$emit('pick', this.activeValue);
+        this.$emit('pick', this.activeValue.slice());
       },
       handleMenuLeave() {
         this.$emit('menuLeave');
@@ -91,7 +91,7 @@
         this.activeValue.splice(menuIndex, len, item.value);
         this.activeOptions.splice(menuIndex + 1, len, item.children);
         if (this.changeOnSelect) {
-          this.$emit('pick', this.activeValue, false);
+          this.$emit('pick', this.activeValue.slice(), false);
         } else {
           this.$emit('activeItemChange', this.activeValue);
         }