diff --git a/web/package.json b/web/package.json
index 73e27cd7d..01250b92a 100644
--- a/web/package.json
+++ b/web/package.json
@@ -7,7 +7,7 @@
         "dev": "vite --host 0.0.0.0 --port 3000",
         "build": "tsc --noEmit && vite build",
         "typecheck": "tsc --noEmit",
-        "test": "bun test test/channel-model-catalog.test.ts test/agent-prompt-cache.test.ts test/canvas-batch-connection.test.ts test/canvas-character-reference.test.ts test/canvas-document.test.ts test/canvas-drawing-engine.test.ts test/canvas-emotion-edit-plan.test.ts test/canvas-folder.test.ts test/canvas-generation-layout.test.ts test/canvas-image-batch-retry.test.ts test/canvas-leafer-viewport.test.ts test/canvas-local-runtime.test.ts test/canvas-model-policy.test.ts test/canvas-resource-references.test.ts test/canvas-storyboard-references.test.ts test/canvas-node-config-reset.test.ts test/canvas-node-registry.test.ts test/canvas-video-regeneration.test.ts test/canvas-video-timeline-segments.test.ts test/create-canvas-handoff.test.ts test/create-library-button.test.ts test/creation-references.test.ts test/generation-asset-repository.node.test.ts test/generation-storage-consistency.test.ts test/generation-task-durability.node.test.ts test/generation-task-local.test.ts test/generation-task-materializer.test.ts test/user-scoped-generation-persistence.test.ts test/local-channel-permission.test.ts test/local-channel-runtime-projection.node.test.mjs test/local-channel-task-center.node.test.mjs test/local-channel-ui.node.test.mjs test/local-cli-settings.test.ts test/local-dreamina-cli.test.ts test/local-dreamina-generation.test.ts test/local-dreamina-model-catalog.test.ts test/local-runtime-bootstrap.test.ts test/local-runtime-connection.test.ts test/local-runtime.test.ts test/client-id.test.ts test/grok-image-prompt-limit.test.ts test/image-resolution-tiers.test.ts test/gemini-image.test.ts test/libtv-import.test.ts test/timeline-to-ffmpeg.test.ts test/canvas-video-segment-args.test.ts test/tapnow-import.test.ts && bun test test/local-dreamina-cross-runtime.test.ts",
+        "test": "bun test test/channel-model-catalog.test.ts test/agent-prompt-cache.test.ts test/canvas-batch-connection.test.ts test/canvas-character-reference.test.ts test/canvas-document.test.ts test/canvas-drawing-engine.test.ts test/canvas-emotion-edit-plan.test.ts test/canvas-folder.test.ts test/canvas-generation-layout.test.ts test/canvas-image-batch-retry.test.ts test/canvas-leafer-viewport.test.ts test/canvas-local-runtime.test.ts test/canvas-model-policy.test.ts test/canvas-resource-references.test.ts test/canvas-storyboard-references.test.ts test/canvas-node-config-reset.test.ts test/canvas-node-registry.test.ts test/canvas-video-regeneration.test.ts test/canvas-video-timeline-segments.test.ts test/create-canvas-handoff.test.ts test/create-library-button.test.ts test/creation-references.test.ts test/generation-asset-repository.node.test.ts test/generation-storage-consistency.test.ts test/generation-task-durability.node.test.ts test/generation-task-local.test.ts test/generation-task-materializer.test.ts test/task-media-fallback.test.ts test/user-scoped-generation-persistence.test.ts test/local-channel-permission.test.ts test/local-channel-runtime-projection.node.test.mjs test/local-channel-task-center.node.test.mjs test/local-channel-ui.node.test.mjs test/local-cli-settings.test.ts test/local-dreamina-cli.test.ts test/local-dreamina-generation.test.ts test/local-dreamina-model-catalog.test.ts test/local-runtime-bootstrap.test.ts test/local-runtime-connection.test.ts test/local-runtime.test.ts test/client-id.test.ts test/grok-image-prompt-limit.test.ts test/image-resolution-tiers.test.ts test/gemini-image.test.ts test/libtv-import.test.ts test/timeline-to-ffmpeg.test.ts test/canvas-video-segment-args.test.ts test/tapnow-import.test.ts && bun test test/local-dreamina-cross-runtime.test.ts",
         "start": "vite preview --host 0.0.0.0 --port 3000",
         "format": "prettier --write .",
         "format:check": "prettier --check ."
diff --git a/web/src/pages/tasks/index.tsx b/web/src/pages/tasks/index.tsx
index 89411fc43..6ba68f27a 100644
--- a/web/src/pages/tasks/index.tsx
+++ b/web/src/pages/tasks/index.tsx
@@ -19,6 +19,7 @@ import { listProjects, type ProjectSummary } from "@/services/api/projects";
 import { TaskGridCard } from "./task-grid-card";
 import { TaskGroupHeader, type TaskGroup } from "./task-group-header";
 import { TaskListRow } from "./task-list-row";
+import { TaskMediaPreview } from "./task-media-preview";
 import { formatModelName, getTaskCanvasContext, isTaskFailed, providerCancelStatusLabel, taskMediaKind } from "./task-shared";
 import { TaskStatusFilterBar, type TaskStatusFilter } from "./task-status-filter";
 
@@ -585,9 +586,16 @@ export default function TasksPage() {
                 destroyOnHidden
                 className="library-modal task-media-preview-modal"
             >
-                {mediaPreview?.kind === "video"
-                    ? <video src={mediaPreview.url} className="max-h-[76vh] w-full bg-black object-contain" controls playsInline preload="metadata" />
-                    : mediaPreview ? <img src={mediaPreview.url} alt={mediaPreview.title} className="max-h-[76vh] w-full bg-black object-contain" /> : null}
+                {mediaPreview ? (
+                    <TaskMediaPreview
+                        src={mediaPreview.url}
+                        kind={mediaPreview.kind}
+                        alt={mediaPreview.title}
+                        controls={mediaPreview.kind === "video"}
+                        className="max-h-[76vh] w-full bg-black object-contain"
+                        fallbackClassName="task-media-preview-unavailable"
+                    />
+                ) : null}
             </Modal>
         </>
     );
@@ -617,9 +625,20 @@ function TaskResultMedia({ value, taskType }: { value?: string; taskType: string
         <div>
             <Typography.Text strong>生成结果</Typography.Text>
             <div className="mt-2 grid max-h-[360px] grid-cols-2 gap-2 overflow-auto rounded-lg bg-stone-950 p-2 md:grid-cols-3">
-                {urls.map((url, index) => isVideoResult(url, taskType)
-                    ? <video key={`${url}-${index}`} src={url} className="aspect-video w-full rounded-md bg-black object-contain" controls preload="metadata" />
-                    : <img key={`${url}-${index}`} src={url} alt={`生成结果 ${index + 1}`} className="aspect-square w-full rounded-md bg-black object-contain" />)}
+                {urls.map((url, index) => {
+                    const isVideo = isVideoResult(url, taskType);
+                    return (
+                        <TaskMediaPreview
+                            key={`${url}-${index}`}
+                            src={url}
+                            kind={isVideo ? "video" : "image"}
+                            alt={`生成结果 ${index + 1}`}
+                            controls={isVideo}
+                            className={isVideo ? "task-result-media is-video" : "task-result-media"}
+                            fallbackClassName={isVideo ? "task-result-media is-video" : "task-result-media"}
+                        />
+                    );
+                })}
             </div>
         </div>
     );
diff --git a/web/src/pages/tasks/task-grid-card.tsx b/web/src/pages/tasks/task-grid-card.tsx
index b85f2f72f..756ea3d40 100644
--- a/web/src/pages/tasks/task-grid-card.tsx
+++ b/web/src/pages/tasks/task-grid-card.tsx
@@ -4,6 +4,7 @@ import { Eye, FileText, Image as ImageIcon, RotateCcw, Video, X } from "lucide-r
 import { CONTENT_MODERATION_ERROR_CODE, isContentModerationError } from "@/lib/generation-error";
 import { statusLabel } from "@/lib/generation-task-display";
 import type { GenerationTask } from "@/services/api/task-center";
+import { TaskMediaPreview } from "./task-media-preview";
 import { isTaskFailed, statusDotClassName, TaskDate } from "./task-shared";
 
 export function TaskGridCard({ task, actingId, onOpen, onRetry, onCancel }: { task: GenerationTask; actingId: string; onOpen: () => void; onRetry: () => void; onCancel: () => void }) {
@@ -16,11 +17,7 @@ export function TaskGridCard({ task, actingId, onOpen, onRetry, onCancel }: { ta
         <article className={`task-grid-card${isFailed ? " is-attention" : ""}`}>
             <div className="task-grid-thumb">
                 {task.previewUrl ? (
-                    isVideo ? (
-                        <video src={task.previewUrl} muted playsInline preload="metadata" className="h-full w-full object-cover" />
-                    ) : (
-                        <img src={task.previewUrl} alt="" loading="lazy" className="h-full w-full object-cover" />
-                    )
+                    <TaskMediaPreview src={task.previewUrl} kind={isVideo ? "video" : "image"} loading="lazy" className="h-full w-full object-cover" />
                 ) : (
                     <Icon />
                 )}
diff --git a/web/src/pages/tasks/task-list-row.tsx b/web/src/pages/tasks/task-list-row.tsx
index df52d7f5e..b79ecc982 100644
--- a/web/src/pages/tasks/task-list-row.tsx
+++ b/web/src/pages/tasks/task-list-row.tsx
@@ -1,10 +1,12 @@
 import { Button, Tooltip } from "antd";
 import { Eye, FileText, FolderKanban, Image as ImageIcon, Play, RotateCcw, Video, X } from "lucide-react";
+import { useState } from "react";
 
 import { CONTENT_MODERATION_ERROR_CODE, generationErrorMessage, isContentModerationError } from "@/lib/generation-error";
 import { formatTaskKind, statusLabel } from "@/lib/generation-task-display";
 import type { GenerationTask } from "@/services/api/task-center";
 import type { AiConfig } from "@/stores/use-config-store";
+import { TaskMediaPreview } from "./task-media-preview";
 import { formatModelName, getTaskCanvasContext, isTaskFailed, statusDotClassName, taskAttentionReason, TaskBilling, TaskDate } from "./task-shared";
 
 export function TaskListRow({
@@ -105,6 +107,8 @@ export function TaskListRow({
 function TaskPreviewThumbnail({ task, onOpen }: { task: GenerationTask; onOpen: () => void }) {
     const isVideo = task.previewKind === "video";
     const fallbackVideo = task.type.includes("video");
+    const [unavailableUrl, setUnavailableUrl] = useState("");
+    const previewUnavailable = Boolean(task.previewUrl && unavailableUrl === task.previewUrl);
     if (!task.previewUrl) {
         const Icon = fallbackVideo ? Video : task.type.includes("image") ? ImageIcon : FileText;
         return (
@@ -114,15 +118,20 @@ function TaskPreviewThumbnail({ task, onOpen }: { task: GenerationTask; onOpen:
         );
     }
     return (
-        <button type="button" onClick={onOpen} className="task-record-thumb group focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring" aria-label={isVideo ? "放大预览生成视频" : "放大预览生成图片"}>
-            {isVideo ? (
-                <video src={task.previewUrl} width={68} height={48} muted playsInline preload="metadata" className="h-full w-full object-cover" />
-            ) : (
-                <img src={task.previewUrl} alt="" width={68} height={48} loading="lazy" className="h-full w-full object-cover" />
-            )}
-            <span className="absolute inset-0 grid place-items-center bg-black/0 text-white opacity-0 transition-[background-color,opacity] duration-150 group-hover:bg-black/30 group-hover:opacity-100 group-focus-visible:bg-black/30 group-focus-visible:opacity-100">
-                {isVideo ? <Play className="size-4 fill-current" /> : <Eye className="size-4" />}
-            </span>
+        <button
+            type="button"
+            onClick={onOpen}
+            disabled={previewUnavailable}
+            className="task-record-thumb group focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
+            aria-label={previewUnavailable ? "预览不可用，素材可能已删除" : isVideo ? "放大预览生成视频" : "放大预览生成图片"}
+            title={previewUnavailable ? "预览不可用，素材可能已删除" : undefined}
+        >
+            <TaskMediaPreview src={task.previewUrl} kind={isVideo ? "video" : "image"} width={68} height={48} loading="lazy" className="h-full w-full object-cover" fallbackLabel="预览不可用" onUnavailable={() => setUnavailableUrl(task.previewUrl || "")} />
+            {!previewUnavailable ? (
+                <span className="absolute inset-0 grid place-items-center bg-black/0 text-white opacity-0 transition-[background-color,opacity] duration-150 group-hover:bg-black/30 group-hover:opacity-100 group-focus-visible:bg-black/30 group-focus-visible:opacity-100">
+                    {isVideo ? <Play className="size-4 fill-current" /> : <Eye className="size-4" />}
+                </span>
+            ) : null}
         </button>
     );
 }
diff --git a/web/src/pages/tasks/task-media-preview.tsx b/web/src/pages/tasks/task-media-preview.tsx
new file mode 100644
index 000000000..0d2c7b11a
--- /dev/null
+++ b/web/src/pages/tasks/task-media-preview.tsx
@@ -0,0 +1,55 @@
+import { ImageOff } from "lucide-react";
+import { useState } from "react";
+
+import { cn } from "@/lib/utils";
+
+const DEFAULT_UNAVAILABLE_LABEL = "预览不可用，素材可能已删除";
+
+export function TaskMediaPreview({
+    src,
+    kind,
+    alt = "",
+    className,
+    fallbackClassName,
+    fallbackLabel = DEFAULT_UNAVAILABLE_LABEL,
+    controls = false,
+    loading,
+    width,
+    height,
+    onUnavailable,
+}: {
+    src: string;
+    kind: "image" | "video";
+    alt?: string;
+    className?: string;
+    fallbackClassName?: string;
+    fallbackLabel?: string;
+    controls?: boolean;
+    loading?: "eager" | "lazy";
+    width?: number;
+    height?: number;
+    onUnavailable?: () => void;
+}) {
+    const [failedSrc, setFailedSrc] = useState("");
+    const unavailable = failedSrc === src;
+
+    const handleUnavailable = () => {
+        setFailedSrc(src);
+        onUnavailable?.();
+    };
+
+    if (unavailable) {
+        return (
+            <span className={cn("task-media-unavailable", fallbackClassName)} role="img" aria-label={fallbackLabel} title={fallbackLabel}>
+                <ImageOff aria-hidden="true" />
+                <span>{fallbackLabel}</span>
+            </span>
+        );
+    }
+
+    if (kind === "video") {
+        return <video src={src} width={width} height={height} muted={!controls} playsInline controls={controls} preload="metadata" className={className} onError={handleUnavailable} />;
+    }
+
+    return <img src={src} alt={alt} width={width} height={height} loading={loading} className={className} onError={handleUnavailable} />;
+}
diff --git a/web/src/styles/globals.css b/web/src/styles/globals.css
index 67c946c0f..159fbbd70 100644
--- a/web/src/styles/globals.css
+++ b/web/src/styles/globals.css
@@ -4334,6 +4334,10 @@
     .task-record-thumb { position: relative; display: grid; width: 84px; height: 60px; flex: 0 0 auto; place-items: center; overflow: hidden; border: 0; border-radius: var(--r-md); background: color-mix(in srgb, var(--foreground) 4%, transparent); padding: 0; color: color-mix(in srgb, var(--foreground) 28%, transparent); }
     /* 媒体脱离 Grid 固有尺寸计算，避免竖图按原始宽高比把固定缩略图撑出任务行。 */
     .task-record-thumb img, .task-record-thumb video { position: absolute; inset: 0; display: block; width: 100%; height: 100%; object-fit: cover; }
+    /* 资源已被删除或失效时，由组件接管原生破图，任务记录本身仍保持可读。 */
+    .task-media-unavailable { display: flex; width: 100%; height: 100%; flex-direction: column; align-items: center; justify-content: center; gap: 5px; color: color-mix(in srgb, var(--foreground) 38%, transparent); font-size: var(--fs-tiny); line-height: 1.25; text-align: center; }
+    .task-media-unavailable > svg { width: 18px; height: 18px; flex: 0 0 auto; }
+    .task-record-thumb:disabled { cursor: default; }
     .task-record-meta { display: flex; min-width: 0; align-items: center; gap: 8px; margin-top: 7px; overflow: hidden; color: color-mix(in srgb, var(--foreground) 40%, transparent); font-size: var(--fs-label); white-space: nowrap; }
     .task-record-meta-canvas { display: inline-flex; min-width: 0; align-items: center; gap: 4px; overflow: hidden; text-overflow: ellipsis; }
     .task-record-meta-canvas svg { flex: 0 0 auto; opacity: .7; }
@@ -4387,6 +4391,7 @@
     .task-grid-card.is-attention .task-grid-body { background: color-mix(in srgb, var(--palette-status-error) 5%, transparent); }
     .task-grid-thumb { position: relative; display: grid; aspect-ratio: 16 / 9; place-items: center; overflow: hidden; background: color-mix(in srgb, var(--foreground) 4%, transparent); color: color-mix(in srgb, var(--foreground) 30%, transparent); }
     .task-grid-thumb > svg { width: 26px; height: 26px; }
+    .task-grid-thumb .task-media-unavailable > svg { width: 26px; height: 26px; }
     .task-grid-thumb img, .task-grid-thumb video { width: 100%; height: 100%; object-fit: cover; }
     .task-grid-overlay { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; gap: 6px; background: color-mix(in srgb, var(--background) 58%, transparent); opacity: 0; backdrop-filter: blur(3px); -webkit-backdrop-filter: blur(3px); transition: opacity 200ms ease-out; }
     .task-grid-card:hover .task-grid-overlay, .task-grid-card:focus-within .task-grid-overlay { opacity: 1; }
@@ -4411,6 +4416,9 @@
     .task-detail-facts { gap: 2px; border-radius: var(--r-md); background: color-mix(in srgb, var(--foreground) 2.5%, transparent); padding: 4px; }
     .task-detail-fact { border-radius: var(--r-sm); }
     .task-detail-error { border-radius: var(--r-md); background: color-mix(in srgb, var(--palette-status-error) 8%, transparent); color: color-mix(in srgb, var(--palette-status-error) 78%, var(--foreground)); }
+    .task-result-media { aspect-ratio: 1; width: 100%; border-radius: var(--r-md); object-fit: contain; }
+    .task-result-media.is-video { aspect-ratio: 16 / 9; }
+    .task-media-preview-unavailable { aspect-ratio: 16 / 9; max-height: 76vh; background: color-mix(in srgb, var(--foreground) 4%, transparent); }
 
     /* 项目概览：原本是「有边框的浅色盒子 + 一堆等重小字」，层级读不出来。
        改成：主区留白撑开、标题字阶拉高、右栏用背景色而非边框分隔、流水线行给足行高。 */
diff --git a/web/test/task-media-fallback.test.ts b/web/test/task-media-fallback.test.ts
new file mode 100644
index 000000000..15e429770
--- /dev/null
+++ b/web/test/task-media-fallback.test.ts
@@ -0,0 +1,29 @@
+import { describe, expect, test } from "bun:test";
+import { readFileSync } from "node:fs";
+import { resolve } from "node:path";
+
+function source(path: string) {
+    return readFileSync(resolve(import.meta.dir, path), "utf8");
+}
+
+describe("task media fallback", () => {
+    test("replaces failed image and video elements with an unavailable state", () => {
+        const preview = source("../src/pages/tasks/task-media-preview.tsx");
+
+        expect(preview).toContain("failedSrc === src");
+        expect(preview).toContain("onError={handleUnavailable}");
+        expect(preview).toContain("预览不可用，素材可能已删除");
+        expect(preview).toContain("<ImageOff");
+    });
+
+    test("uses the fallback in list, grid, detail and enlarged previews", () => {
+        const list = source("../src/pages/tasks/task-list-row.tsx");
+        const grid = source("../src/pages/tasks/task-grid-card.tsx");
+        const page = source("../src/pages/tasks/index.tsx");
+
+        expect(list).toContain("<TaskMediaPreview");
+        expect(list).toContain("disabled={previewUnavailable}");
+        expect(grid).toContain("<TaskMediaPreview");
+        expect(page.match(/<TaskMediaPreview/g)).toHaveLength(2);
+    });
+});