diff --git a/packages/slider/index.ts b/packages/slider/index.ts
index 742a1ee1..f0c04cb1 100644
--- a/packages/slider/index.ts
+++ b/packages/slider/index.ts
@@ -32,7 +32,7 @@ VantComponent({
   },
 
   watch: {
-    value(value) {
+    value(value: number) {
       this.updateValue(value, false);
     }
   },
@@ -53,7 +53,7 @@ VantComponent({
       if (this.data.disabled) return;
 
       this.touchMove(event);
-      this.getRect('.van-slider').then(rect => {
+      this.getRect('.van-slider').then((rect: wx.BoundingClientRectCallbackResult) => {
         const diff = this.deltaX / rect.width * 100;
         this.updateValue(this.startValue + diff, false, true);
       });
@@ -67,13 +67,13 @@ VantComponent({
     onClick(event: Weapp.TouchEvent) {
       if (this.data.disabled) return;
 
-      this.getRect(rect => {
+      this.getRect('.van-slider').then((rect: wx.BoundingClientRectCallbackResult) => {
         const value = (event.detail.x - rect.left) / rect.width * 100;
         this.updateValue(value, true);
       });
     },
 
-    updateValue(value, end, drag) {
+    updateValue(value: number, end: boolean, drag: boolean) {
       value = this.format(value);
 
       this.set({
@@ -84,13 +84,13 @@ VantComponent({
       if (drag) {
         this.$emit('drag', { value });
       }
-      
+
       if (end) {
         this.$emit('change', value);
       }
     },
 
-    format(value) {
+    format(value: number) {
       const { max, min, step } = this.data;
       return Math.round(Math.max(min, Math.min(value, max)) / step) * step;
     }
diff --git a/packages/slider/index.wxml b/packages/slider/index.wxml
index e57d1e9c..d30d078b 100644
--- a/packages/slider/index.wxml
+++ b/packages/slider/index.wxml
@@ -1,5 +1,7 @@
+<wxs src="../wxs/utils.wxs" module="utils" />
+
 <view
-  class="custom-class van-slider {{ disabled ? 'van-slider--disabled' : '' }}"
+  class="custom-class {{ utils.bem('slider', { disabled }) }}"
   style="{{ inactiveColor ? 'background:' + inactiveColor : '' }}"
   bind:tap="onClick"
 >