diff --git a/packages/design-core/index.js b/packages/design-core/index.js
index 5acb5ee87..404b205cc 100644
--- a/packages/design-core/index.js
+++ b/packages/design-core/index.js
@@ -30,7 +30,7 @@ export { default as Robot } from '@opentiny/tiny-engine-plugin-robot'
 export { default as Props, PropertiesService, PropertyService } from '@opentiny/tiny-engine-setting-props'
 export { default as Events } from '@opentiny/tiny-engine-setting-events'
 export { default as Styles } from '@opentiny/tiny-engine-setting-styles'
-export { default as Layout, LayoutService } from '@opentiny/tiny-engine-layout'
+export { default as Layout, ToolbarBaseComponent, LayoutService } from '@opentiny/tiny-engine-layout'
 export { default as Canvas } from '@opentiny/tiny-engine-canvas'
 export { initPreview } from './src/preview/src/main'
 export { GenerateCodeService, PluginPanel } from '@opentiny/tiny-engine-common'
diff --git a/packages/layout/src/DesignToolbars.vue b/packages/layout/src/DesignToolbars.vue
index 38a4dc40c..f1f4f7dad 100644
--- a/packages/layout/src/DesignToolbars.vue
+++ b/packages/layout/src/DesignToolbars.vue
@@ -111,6 +111,7 @@ export default {
   }
 
   .toolbar-left,
+  .toolbar-center,
   .toolbar-right {
     :deep(.icon) {
       display: inline-flex;
diff --git a/packages/toolbars/preview/meta.js b/packages/toolbars/preview/meta.js
index 68549dae3..535f72a16 100644
--- a/packages/toolbars/preview/meta.js
+++ b/packages/toolbars/preview/meta.js
@@ -7,5 +7,7 @@ export default {
   },
   align: 'right',
   renderType: 'icon',
-  options: {}
+  options: {
+    useDefaultClass: true
+  }
 }