diff --git a/apps/web/src/pages/generate/components/material/ManualMaterialList.tsx b/apps/web/src/pages/generate/components/material/ManualMaterialList.tsx
index 61a8bd6ba..112bddaee 100644
--- a/apps/web/src/pages/generate/components/material/ManualMaterialList.tsx
+++ b/apps/web/src/pages/generate/components/material/ManualMaterialList.tsx
@@ -33,7 +33,9 @@ const ManualMaterialList: React.FC<ManualMaterialListProps> = ({
           {materials.items.map((m) => {
             const checked = selectedMaterials.includes(m.id)
             const isVideo = m.mime_type?.startsWith("video/") ?? false
-            const thumbSrc = m.thumbnail_url || (isVideo ? m.file_url : undefined)
+            // thumbnail_url 是静态截图，可直接用于 <img>
+            // file_url 是视频/音频文件本身，<img> 无法渲染，不能作为 src 回退
+            const thumbSrc = m.thumbnail_url || undefined
             return (
               <label
                 key={m.id}