diff --git a/src/dialog/README.md b/src/dialog/README.md
index 08482dee2..d5b958c86 100644
--- a/src/dialog/README.md
+++ b/src/dialog/README.md
@@ -129,6 +129,7 @@ export default {
 | confirmButtonText | Confirm button text | *string* | `Confirm` | - |
 | confirmButtonColor | Confirm button color | *string* | `#1989fa` | - |
 | overlay | Whether to show overlay | *boolean* | `true` | - |
+| overlayClass | Custom overlay class | *string* | - | 2.2.7 |
 | overlayStyle | Custom overlay style | *object* | - | 2.2.7 |
 | closeOnPopstate | Whether to close when popstate | *boolean* | `false` | 2.0.5 |
 | closeOnClickOverlay | Whether to close when click overlay | *boolean* | `false` | - |
@@ -152,6 +153,7 @@ export default {
 | confirm-button-text | Confirm button text | *string* | `Confirm` | - |
 | confirm-button-color | Confirm button color | *string* | `#1989fa` | - |
 | overlay | Whether to show overlay | *boolean* | `true` | - |
+| overlay-class | Custom overlay class | *string* | - | 2.2.7 |
 | overlay-style | Custom overlay style | *object* | - | 2.2.7 |
 | close-on-popstate | Whether to close when popstate | *boolean* | `false` | 2.0.5 |
 | close-on-click-overlay | Whether to close when click overlay | *boolean* | `false` | - |
diff --git a/src/dialog/README.zh-CN.md b/src/dialog/README.zh-CN.md
index 63356aa6c..a1f408351 100644
--- a/src/dialog/README.zh-CN.md
+++ b/src/dialog/README.zh-CN.md
@@ -158,6 +158,7 @@ export default {
 | cancelButtonText | 取消按钮文案 | *string* | `取消` | - |
 | cancelButtonColor | 取消按钮颜色 | *string* | `#000` | - |
 | overlay | 是否展示遮罩层 | *boolean* | `true` | - |
+| overlayClass | 自定义遮罩层类名 | *string* | - | 2.2.7 |
 | overlayStyle | 自定义遮罩层样式 | *object* | - | 2.2.7 |
 | closeOnPopstate | 是否在页面回退时自动关闭 | *boolean* | `false` | 2.0.5 |
 | closeOnClickOverlay | 是否在点击遮罩层后关闭弹窗 | *boolean* | `false` | - |
@@ -183,6 +184,7 @@ export default {
 | cancel-button-text | 取消按钮文案 | *string* | `取消` | - |
 | cancel-button-color | 取消按钮颜色 | *string* | `#000` | - |
 | overlay | 是否展示遮罩层 | *boolean* | `true` | - |
+| overlay-class | 自定义遮罩层类名 | *string* | - | 2.2.7 |
 | overlay-style | 自定义遮罩层样式 | *object* | - | 2.2.7 |
 | close-on-popstate | 是否在页面回退时自动关闭 | *boolean* | `false` | 2.0.5 |
 | close-on-click-overlay | 是否在点击遮罩层后关闭弹窗 | *boolean* | `false` | - |
diff --git a/src/dialog/index.js b/src/dialog/index.js
index 075dade2e..adb40482a 100644
--- a/src/dialog/index.js
+++ b/src/dialog/index.js
@@ -53,6 +53,7 @@ Dialog.defaultOptions = {
   lockScroll: true,
   transition: 'van-dialog-bounce',
   beforeClose: null,
+  overlayClass: '',
   overlayStyle: null,
   messageAlign: '',
   getContainer: 'body',
diff --git a/types/dialog.d.ts b/types/dialog.d.ts
index 3b0c4f167..f413e972a 100644
--- a/types/dialog.d.ts
+++ b/types/dialog.d.ts
@@ -9,6 +9,7 @@ export type DialogOptions = {
   lockScroll?: boolean;
   transition?: string;
   messageAlign?: string;
+  overlayClass?: string;
   overlayStyle?: object;
   closeOnPopstate?: boolean;
   cancelButtonText?: string;