diff --git a/src/components/sideBar/index.tsx b/src/components/sideBar/index.tsx
index 3451dcf..ef763a4 100644
--- a/src/components/sideBar/index.tsx
+++ b/src/components/sideBar/index.tsx
@@ -61,6 +61,21 @@ const SideBar = ({
     }
   }
 
+  useEffect(() => {
+    Taro.nextTick(() => {
+      const query = Taro.createSelectorQuery()
+      query.select('.side_bar_select').boundingClientRect((rect) => {
+        console.log('rect::', rect)
+        const clientHeight = rect.height
+        const clientWidth = rect.width
+        const ratio = 750 / clientWidth
+        const height = clientHeight * ratio
+        num_half.current = Math.ceil(height / 2 / heightItem)
+        init()
+      }).exec()
+    })
+  }, [])
+
   const clickEvent = ({ item, index }: { item; index: number }) => {
     setSelected(item.id)
     sideBarOnClick?.(item)