diff --git a/src/components/hazard_inspect/timeline/timeline.css b/src/components/hazard_inspect/timeline/timeline.css
index 2b55bed..8010248 100644
--- a/src/components/hazard_inspect/timeline/timeline.css
+++ b/src/components/hazard_inspect/timeline/timeline.css
@@ -98,9 +98,19 @@
   top: 0;
   bottom: 0;
   width: 2px;
-  background-color: #ef4444;
   z-index: 25;
   cursor: ew-resize;
+  transform: translateZ(0);
+}
+
+.playhead::before {
+  content: '';
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 2px;
+  height: 100%;
+  background-color: #ef4444;
 }
 
 .playhead-indicator {
diff --git a/src/components/hazard_inspect/timeline/timeline.ts b/src/components/hazard_inspect/timeline/timeline.ts
index 005f3d6..aee1319 100644
--- a/src/components/hazard_inspect/timeline/timeline.ts
+++ b/src/components/hazard_inspect/timeline/timeline.ts
@@ -64,6 +64,7 @@ export function useTimeline(
   const isPlayheadDragging = ref(false)
   const isRulerDragging = ref(false)
   const isMounted = ref(false)
+  const displayFrame = ref(0)
   const dragStartX = ref(0)
   const scrollStartLeft = ref(0)
   const localCurrentFrame = ref(0)
@@ -121,18 +122,16 @@ export function useTimeline(
     // 计算缩放前后的位置偏移
     // console.log('container.scrollLeft', container.scrollLeft)
     if (playheadVisible) {
-      // 以播放头为中心缩放
       const playheadX = playheadPosition - containerScrollLeft
       const newPlayheadPosition = props.currentFrame * newPxPerFrame
-      const newScrollLeft = newPlayheadPosition - playheadX
+      const newScrollLeft = Math.round(newPlayheadPosition - playheadX)
       container.scrollLeft = newScrollLeft
     }
     else {
-      // 以容器中心为中心缩放
       const centerX = containerWidth / 2
       const centerPosition = containerScrollLeft + centerX
       const newCenterPosition = centerPosition * (newPxPerFrame / oldPxPerFrame)
-      container.scrollLeft = newCenterPosition - centerX
+      container.scrollLeft = Math.round(newCenterPosition - centerX)
     }
 
     // 最后更新缩放值
@@ -175,9 +174,7 @@ export function useTimeline(
   }
 
   const playheadPos: ComputedRef<number> = computed(() => {
-    const frame = isPlayheadDragging.value ? localCurrentFrame.value : props.currentFrame
-    const clampedFrame = Math.max(0, Math.min(frame, props.totalFrames - 1))
-    return clampedFrame * pxPerFrame.value
+    return Math.round(displayFrame.value * pxPerFrame.value)
   })
 
   const trackRows: ComputedRef<HazardRow[][]> = computed(() => {
@@ -260,6 +257,15 @@ export function useTimeline(
     if (!timelineContainer.value)
       return
     e.preventDefault()
+
+    if (e.shiftKey) {
+      const delta = e.deltaY || e.deltaX
+      const zoomDelta = delta > 0 ? -0.1 : 0.1
+      const newZoom = pxPerFrame.value + zoomDelta
+      setZoom(newZoom)
+      return
+    }
+
     const container = timelineContainer.value
     const delta = e.deltaY || e.deltaX
     container.scrollLeft += delta
@@ -318,6 +324,7 @@ export function useTimeline(
     const frame = Math.floor(x / pxPerFrame.value)
     const clampedFrame = Math.max(0, Math.min(frame, props.totalFrames - 1))
     localCurrentFrame.value = clampedFrame
+    displayFrame.value = clampedFrame
     emit('frameChange', clampedFrame)
   }
 
@@ -330,13 +337,16 @@ export function useTimeline(
     const frame = Math.floor(x / pxPerFrame.value)
     const clampedFrame = Math.max(0, Math.min(frame, props.totalFrames - 1))
     localCurrentFrame.value = clampedFrame
+    displayFrame.value = clampedFrame
     emit('frameChange', clampedFrame)
   }
 
   watch(() => props.currentFrame, () => {
-    if (!isPlayheadDragging.value) {
-      localCurrentFrame.value = props.currentFrame
-    }
+    if (isPlayheadDragging.value)
+      return
+
+    displayFrame.value = props.currentFrame
+
     nextTick(() => {
       if (!timelineContainer.value)
         return
@@ -408,7 +418,7 @@ export function useTimeline(
     isDragging,
     isPlayheadDragging,
     isRulerDragging,
-    localCurrentFrame,
+    displayFrame,
     trackWidth,
     timeTicks,
     secondTicks,
diff --git a/src/components/hazard_inspect/timeline/timeline.vue b/src/components/hazard_inspect/timeline/timeline.vue
index 2d626fd..dadfb2c 100644
--- a/src/components/hazard_inspect/timeline/timeline.vue
+++ b/src/components/hazard_inspect/timeline/timeline.vue
@@ -50,7 +50,7 @@ onUnmounted(() => {
         <el-button
           type="info" dashed :icon="InfoFilled" size="small"
           @click="openMessageBox(
-            '拖动播放头控制播放进度。滚轮/拖动时间轴前后移动。点击隐患编号跳转对应隐患。',
+            '拖动播放头 控制播放进度。滚轮/拖动 时间轴前后移动。点击隐患编号跳转对应隐患。shift键+鼠标滚轮 缩放时间轴。',
             '操作说明',
           )"
         >