diff --git a/apps/web/src/pages/generate/hooks/useCanvasPlayer.ts b/apps/web/src/pages/generate/hooks/useCanvasPlayer.ts
index b3f69f117..699661b86 100644
--- a/apps/web/src/pages/generate/hooks/useCanvasPlayer.ts
+++ b/apps/web/src/pages/generate/hooks/useCanvasPlayer.ts
@@ -81,6 +81,47 @@ function findCodecConfigRecursive(
   return undefined
 }
 
+/**
+ * 从 MP4 buffer 中解析视频轨道的旋转角度。
+ * iOS HEVC 竖屏视频用 rotation=90° 元数据标记，
+ * mp4box.js 的 track_width/track_height 不反映旋转后的尺寸。
+ */
+function extractVideoRotation(buffer: ArrayBuffer): number {
+  try {
+    const view = new DataView(buffer)
+    let offset = 0
+    while (offset < buffer.byteLength - 8) {
+      const size = view.getUint32(offset)
+      const type = String.fromCharCode(
+        view.getUint8(offset + 4),
+        view.getUint8(offset + 5),
+        view.getUint8(offset + 6),
+        view.getUint8(offset + 7),
+      )
+      if (size <= 0 || offset + size > buffer.byteLength) break
+      if (type === "tkhd") {
+        const version = view.getUint8(offset + 8)
+        const matrixOffset = offset + (version === 0 ? 28 : 40)
+        if (matrixOffset + 36 <= offset + size) {
+          const a = view.getInt32(matrixOffset)
+          const b = view.getInt32(matrixOffset + 4)
+          if (Math.abs(b) > 0x00008000) {
+            return b > 0 ? 90 : 270
+          }
+          if (a < -0x00008000) {
+            return 180
+          }
+          return 0
+        }
+      }
+      offset += size
+    }
+  } catch {
+    // 解析失败不阻塞，返回 0
+  }
+  return 0
+}
+
 // ── 帧队列（环形缓冲区） ──
 interface FrameEntry {
   frame: VideoFrame
@@ -370,6 +411,18 @@ export function useCanvasPlayer(
             samples: [],
           }
 
+          // ═══ 新增：检测旋转元数据，交换宽高 ═══
+          const rotation = extractVideoRotation(buffer)
+          if (rotation === 90 || rotation === 270) {
+            const tmpW = meta.videoWidth
+            meta.videoWidth = meta.videoHeight
+            meta.videoHeight = tmpW
+            console.log(
+              `[useCanvasPlayer] Rotation ${rotation}° detected, swapped dimensions to ${meta.videoWidth}x${meta.videoHeight}`,
+            )
+          }
+          // ═══ 新增结束 ═══
+
           // 提取所有 samples
           mp4File.setExtractionOptions(videoTrack.id ?? 1, null, {
             nbSamples: Infinity, // 提取所有 sample
@@ -479,6 +532,15 @@ export function useCanvasPlayer(
       })
 
       try {
+        // ═══ 新增：旋转检测 ═══
+        const rotation = extractVideoRotation(_buffer)
+        if (rotation === 90 || rotation === 270) {
+          const tmpW = meta.videoWidth
+          meta.videoWidth = meta.videoHeight
+          meta.videoHeight = tmpW
+        }
+        // ═══ 新增结束 ═══
+
         await decoder.configure({
           codec: meta.codec,
           codedWidth: meta.videoWidth,