diff --git a/src/index.js b/src/index.js
index f0b4704..aeb2515 100644
--- a/src/index.js
+++ b/src/index.js
@@ -5,6 +5,7 @@ function isExist(field) {
 }
 
 Component({
+  externalClasses: ['picker-class'],
   /**
    * 组件的属性列表
    */
diff --git a/src/index.wxml b/src/index.wxml
index c87126e..d9795fe 100644
--- a/src/index.wxml
+++ b/src/index.wxml
@@ -1,4 +1,5 @@
 <picker 
+  class="picker picker-class"
   mode="multiSelector"
   bindchange="pickerChange"
   bindcolumnchange="pickerColumnChange"
diff --git a/src/index.wxss b/src/index.wxss
index 8b13789..41d4cff 100644
--- a/src/index.wxss
+++ b/src/index.wxss
@@ -1 +1,5 @@
 
+.picker {
+  width: 100%;
+  height: 100%;
+}
\ No newline at end of file