diff --git a/packages/action-sheet/test/__snapshots__/demo.spec.ts.snap b/packages/action-sheet/test/__snapshots__/demo.spec.ts.snap
index 0a70748e..8def4f94 100644
--- a/packages/action-sheet/test/__snapshots__/demo.spec.ts.snap
+++ b/packages/action-sheet/test/__snapshots__/demo.spec.ts.snap
@@ -58,7 +58,7 @@ exports[`should render demo and match snapshot 1`] = `
             bind:click="onClickOverlay"
           >
             <van-transition
-              customClass="van-overlay"
+              customClass="van-overlay custom-class"
               bind:tap="onClick"
               catch:touchmove="noop"
             />
@@ -123,7 +123,7 @@ exports[`should render demo and match snapshot 1`] = `
             bind:click="onClickOverlay"
           >
             <van-transition
-              customClass="van-overlay"
+              customClass="van-overlay custom-class"
               bind:tap="onClick"
               catch:touchmove="noop"
             />
@@ -188,7 +188,7 @@ exports[`should render demo and match snapshot 1`] = `
             bind:click="onClickOverlay"
           >
             <van-transition
-              customClass="van-overlay"
+              customClass="van-overlay custom-class"
               bind:tap="onClick"
               catch:touchmove="noop"
             />
@@ -253,7 +253,7 @@ exports[`should render demo and match snapshot 1`] = `
             bind:click="onClickOverlay"
           >
             <van-transition
-              customClass="van-overlay"
+              customClass="van-overlay custom-class"
               bind:tap="onClick"
               catch:touchmove="noop"
             />
@@ -318,7 +318,7 @@ exports[`should render demo and match snapshot 1`] = `
             bind:click="onClickOverlay"
           >
             <van-transition
-              customClass="van-overlay"
+              customClass="van-overlay custom-class"
               bind:tap="onClick"
               catch:touchmove="noop"
             />
@@ -384,7 +384,7 @@ exports[`should render demo and match snapshot 1`] = `
             bind:click="onClickOverlay"
           >
             <van-transition
-              customClass="van-overlay"
+              customClass="van-overlay custom-class"
               bind:tap="onClick"
               catch:touchmove="noop"
             />
diff --git a/packages/calendar/test/__snapshots__/demo.spec.ts.snap b/packages/calendar/test/__snapshots__/demo.spec.ts.snap
index 583bc080..06fae70e 100644
--- a/packages/calendar/test/__snapshots__/demo.spec.ts.snap
+++ b/packages/calendar/test/__snapshots__/demo.spec.ts.snap
@@ -1712,7 +1712,7 @@ exports[`should render demo and match snapshot 1`] = `
         bind:click="onClickOverlay"
       >
         <van-transition
-          customClass="van-overlay"
+          customClass="van-overlay custom-class"
           bind:tap="onClick"
           catch:touchmove="noop"
         />
diff --git a/packages/dialog/test/__snapshots__/demo.spec.ts.snap b/packages/dialog/test/__snapshots__/demo.spec.ts.snap
index 940ea89a..8f0b0b1b 100644
--- a/packages/dialog/test/__snapshots__/demo.spec.ts.snap
+++ b/packages/dialog/test/__snapshots__/demo.spec.ts.snap
@@ -271,7 +271,7 @@ exports[`should render demo and match snapshot 1`] = `
         bind:click="onClickOverlay"
       >
         <van-transition
-          customClass="van-overlay"
+          customClass="van-overlay custom-class"
           bind:tap="onClick"
           catch:touchmove="noop"
         />
@@ -287,7 +287,7 @@ exports[`should render demo and match snapshot 1`] = `
         bind:click="onClickOverlay"
       >
         <van-transition
-          customClass="van-overlay"
+          customClass="van-overlay custom-class"
           bind:tap="onClick"
           catch:touchmove="noop"
         />
diff --git a/packages/overlay/README.md b/packages/overlay/README.md
index e240534b..fadd3a60 100644
--- a/packages/overlay/README.md
+++ b/packages/overlay/README.md
@@ -107,3 +107,10 @@ Page({
 | 名称 | 说明                               |
 | ---- | ---------------------------------- |
 | -    | 默认插槽，用于在遮罩层上方嵌入内容 |
+
+
+### 外部样式类
+
+| 类名         | 说明         |
+| ------------ | ------------ |
+| custom-class | 根节点样式类 |
diff --git a/packages/overlay/index.wxml b/packages/overlay/index.wxml
index 92734a0c..4ac2c6dd 100644
--- a/packages/overlay/index.wxml
+++ b/packages/overlay/index.wxml
@@ -1,7 +1,7 @@
 <van-transition
   wx:if="{{ lockScroll }}"
   show="{{ show }}"
-  custom-class="van-overlay"
+  custom-class="van-overlay custom-class"
   custom-style="z-index: {{ zIndex }}; {{ customStyle }}"
   duration="{{ duration }}"
   bind:tap="onClick"
@@ -12,7 +12,7 @@
 <van-transition
   wx:else
   show="{{ show }}"
-  custom-class="van-overlay"
+  custom-class="van-overlay custom-class"
   custom-style="z-index: {{ zIndex }}; {{ customStyle }}"
   duration="{{ duration }}"
   bind:tap="onClick"
diff --git a/packages/overlay/test/__snapshots__/demo.spec.ts.snap b/packages/overlay/test/__snapshots__/demo.spec.ts.snap
index d75da373..e2277aed 100644
--- a/packages/overlay/test/__snapshots__/demo.spec.ts.snap
+++ b/packages/overlay/test/__snapshots__/demo.spec.ts.snap
@@ -53,7 +53,7 @@ exports[`should render demo and match snapshot 1`] = `
         bind:click="onClickHide"
       >
         <van-transition
-          customClass="van-overlay"
+          customClass="van-overlay custom-class"
           bind:tap="onClick"
           catch:touchmove="noop"
         />
@@ -111,7 +111,7 @@ exports[`should render demo and match snapshot 1`] = `
         bind:click="onClickHideEmbedded"
       >
         <van-transition
-          customClass="van-overlay"
+          customClass="van-overlay custom-class"
           bind:tap="onClick"
           catch:touchmove="noop"
         />
diff --git a/packages/popup/test/__snapshots__/demo.spec.ts.snap b/packages/popup/test/__snapshots__/demo.spec.ts.snap
index 40d10ab8..a56a4456 100644
--- a/packages/popup/test/__snapshots__/demo.spec.ts.snap
+++ b/packages/popup/test/__snapshots__/demo.spec.ts.snap
@@ -49,7 +49,7 @@ exports[`should render demo and match snapshot 1`] = `
           bind:click="onClickOverlay"
         >
           <van-transition
-            customClass="van-overlay"
+            customClass="van-overlay custom-class"
             bind:tap="onClick"
             catch:touchmove="noop"
           />
@@ -197,7 +197,7 @@ exports[`should render demo and match snapshot 1`] = `
           bind:click="onClickOverlay"
         >
           <van-transition
-            customClass="van-overlay"
+            customClass="van-overlay custom-class"
             bind:tap="onClick"
             catch:touchmove="noop"
           />
@@ -210,7 +210,7 @@ exports[`should render demo and match snapshot 1`] = `
           bind:click="onClickOverlay"
         >
           <van-transition
-            customClass="van-overlay"
+            customClass="van-overlay custom-class"
             bind:tap="onClick"
             catch:touchmove="noop"
           />
@@ -223,7 +223,7 @@ exports[`should render demo and match snapshot 1`] = `
           bind:click="onClickOverlay"
         >
           <van-transition
-            customClass="van-overlay"
+            customClass="van-overlay custom-class"
             bind:tap="onClick"
             catch:touchmove="noop"
           />
@@ -236,7 +236,7 @@ exports[`should render demo and match snapshot 1`] = `
           bind:click="onClickOverlay"
         >
           <van-transition
-            customClass="van-overlay"
+            customClass="van-overlay custom-class"
             bind:tap="onClick"
             catch:touchmove="noop"
           />
@@ -353,7 +353,7 @@ exports[`should render demo and match snapshot 1`] = `
           bind:click="onClickOverlay"
         >
           <van-transition
-            customClass="van-overlay"
+            customClass="van-overlay custom-class"
             bind:tap="onClick"
             catch:touchmove="noop"
           />
@@ -366,7 +366,7 @@ exports[`should render demo and match snapshot 1`] = `
           bind:click="onClickOverlay"
         >
           <van-transition
-            customClass="van-overlay"
+            customClass="van-overlay custom-class"
             bind:tap="onClick"
             catch:touchmove="noop"
           />
@@ -379,7 +379,7 @@ exports[`should render demo and match snapshot 1`] = `
           bind:click="onClickOverlay"
         >
           <van-transition
-            customClass="van-overlay"
+            customClass="van-overlay custom-class"
             bind:tap="onClick"
             catch:touchmove="noop"
           />
@@ -434,7 +434,7 @@ exports[`should render demo and match snapshot 1`] = `
           bind:click="onClickOverlay"
         >
           <van-transition
-            customClass="van-overlay"
+            customClass="van-overlay custom-class"
             bind:tap="onClick"
             catch:touchmove="noop"
           />
diff --git a/packages/share-sheet/test/__snapshots__/demo.spec.ts.snap b/packages/share-sheet/test/__snapshots__/demo.spec.ts.snap
index ccedfb68..3a32b1dc 100644
--- a/packages/share-sheet/test/__snapshots__/demo.spec.ts.snap
+++ b/packages/share-sheet/test/__snapshots__/demo.spec.ts.snap
@@ -59,7 +59,7 @@ exports[`should render demo and match snapshot 1`] = `
               bind:click="onClickOverlay"
             >
               <van-transition
-                customClass="van-overlay"
+                customClass="van-overlay custom-class"
                 bind:tap="onClick"
                 catch:touchmove="noop"
               />
@@ -126,7 +126,7 @@ exports[`should render demo and match snapshot 1`] = `
               bind:click="onClickOverlay"
             >
               <van-transition
-                customClass="van-overlay"
+                customClass="van-overlay custom-class"
                 bind:tap="onClick"
                 catch:touchmove="noop"
               />
@@ -193,7 +193,7 @@ exports[`should render demo and match snapshot 1`] = `
               bind:click="onClickOverlay"
             >
               <van-transition
-                customClass="van-overlay"
+                customClass="van-overlay custom-class"
                 bind:tap="onClick"
                 catch:touchmove="noop"
               />
@@ -260,7 +260,7 @@ exports[`should render demo and match snapshot 1`] = `
               bind:click="onClickOverlay"
             >
               <van-transition
-                customClass="van-overlay"
+                customClass="van-overlay custom-class"
                 bind:tap="onClick"
                 catch:touchmove="noop"
               />
diff --git a/packages/swipe-cell/test/__snapshots__/demo.spec.ts.snap b/packages/swipe-cell/test/__snapshots__/demo.spec.ts.snap
index 56854a7f..2ed138d2 100644
--- a/packages/swipe-cell/test/__snapshots__/demo.spec.ts.snap
+++ b/packages/swipe-cell/test/__snapshots__/demo.spec.ts.snap
@@ -251,7 +251,7 @@ exports[`should render demo and match snapshot 1`] = `
         bind:click="onClickOverlay"
       >
         <van-transition
-          customClass="van-overlay"
+          customClass="van-overlay custom-class"
           bind:tap="onClick"
           catch:touchmove="noop"
         />
diff --git a/packages/switch/test/__snapshots__/demo.spec.ts.snap b/packages/switch/test/__snapshots__/demo.spec.ts.snap
index 8bb49cfd..5740c5c8 100644
--- a/packages/switch/test/__snapshots__/demo.spec.ts.snap
+++ b/packages/switch/test/__snapshots__/demo.spec.ts.snap
@@ -172,7 +172,7 @@ exports[`should render demo and match snapshot 1`] = `
         bind:click="onClickOverlay"
       >
         <van-transition
-          customClass="van-overlay"
+          customClass="van-overlay custom-class"
           bind:tap="onClick"
           catch:touchmove="noop"
         />