diff --git a/src/slider/index.js b/src/slider/index.js
index 393aef9..6b3da72 100644
--- a/src/slider/index.js
+++ b/src/slider/index.js
@@ -204,16 +204,16 @@ class Slider extends Component {
     this.$tips.classList.toggle('show')
     preValue = +preValue || min
 
-    const start = vertical ? e.clientY : e.clientX
-    const onMousemove = bind(document, 'mousemove', e => {
+    let start = vertical ? e.clientY : e.clientX
+    let onMousemove = bind(document, 'mousemove', e => {
       e.preventDefault()
-      const distance = (vertical ? e.clientY : e.clientX) - start
-      const scale =
+      let distance = (vertical ? e.clientY : e.clientX) - start
+      let scale =
         (distance /
           (vertical ? this.$runway.clientHeight : this.$runway.clientWidth)) *
         (vertical ? -1 : 1)
 
-      const diff =
+      let diff =
         accuracy === 0 ? Math.round(scale * (max - min)) : scale * (max - min)
       let newProgress = progress + Math.floor(scale * 100)
       let newValue =
@@ -239,7 +239,7 @@ class Slider extends Component {
       this.$emit('input')
     })
 
-    const onMouseup = bind(document, 'mouseup', () => {
+    let onMouseup = bind(document, 'mouseup', () => {
       unbind(document, 'mousemove', onMousemove)
       unbind(document, 'mouseup', onMouseup)
       this.$tips.classList.toggle('show')
@@ -254,10 +254,10 @@ class Slider extends Component {
     if (disabled || readOnly) {
       return
     }
-    const { clientWidth, clientHeight } = e.target
-    const { offsetX, offsetY } = e
-    const range = max - min
-    const scale =
+    let { clientWidth, clientHeight } = e.target
+    let { offsetX, offsetY } = e
+    let range = max - min
+    let scale =
       (vertical ? offsetY : offsetX) / (vertical ? clientHeight : clientWidth)
 
     step *= Math.pow(10, accuracy)
@@ -266,7 +266,7 @@ class Slider extends Component {
       +(scale * range + min).toFixed(accuracy) * Math.pow(10, accuracy)
     let mod = +(newValue % step).toFixed(accuracy)
     if (mod) {
-      const half = step / 2
+      let half = step / 2
       if (mod > half) {
         newValue += step - mod
       } else {
@@ -276,7 +276,7 @@ class Slider extends Component {
 
     newValue *= Math.pow(10, -accuracy)
     this.value = (vertical ? range - newValue : newValue).toFixed(accuracy)
-    const progress = Math.floor(((newValue - min) / range) * 100)
+    let progress = Math.floor(((newValue - min) / range) * 100)
     this.setProgress(progress)
     this.$emit('change')
     this.$emit('input')
@@ -292,11 +292,11 @@ class Slider extends Component {
     }, 1000)
   }
   initValue(val) {
-    const { max, min, vertical, disabled, readOnly } = this
+    let { max, min, vertical, disabled, readOnly } = this
     if (disabled || readOnly) {
       return
     }
-    const range = max - min
+    let range = max - min
     val = Math.max(val, min)
     val = Math.min(val, max)
     this.value = val
@@ -305,7 +305,7 @@ class Slider extends Component {
     this.setProgress(progress)
   }
   setProgress(val) {
-    const { vertical } = this
+    let { vertical } = this
     val = Math.floor(val)
     val = Math.min(val, 100)
     val = Math.max(val, 0)