diff --git a/app/api/canvas/detail-plan/route.ts b/app/api/canvas/detail-plan/route.ts
index 1d8274257..9bd096b08 100644
--- a/app/api/canvas/detail-plan/route.ts
+++ b/app/api/canvas/detail-plan/route.ts
@@ -11,6 +11,7 @@ import {
 } from "@/lib/db/ai-model-flags";
 import { getLanguageModelById } from "@/lib/ai/dynamic-provider";
 import { inlineVisionImages } from "@/lib/ai/vision-inline";
+import { filterReachableRemoteUrls } from "@/lib/net/url-access";
 
 export const runtime = "nodejs";
 export const maxDuration = 180;
@@ -1669,10 +1670,37 @@ export async function POST(request: Request) {
     }
 
     const baseCount = clampCount(body.count);
-    const referenceImages = sanitizeReferenceImages(body.referenceImages);
+    const referenceImagesRaw = sanitizeReferenceImages(body.referenceImages);
     const referenceImageNotes = sanitizeReferenceImageNotes(body.referenceImageNotes);
-    const modelImageUrl = String(body.modelImageUrl || "").trim();
-    const bundleImageUrls = sanitizeBundleImages(body.bundleImageUrls);
+    const modelImageUrlRaw = String(body.modelImageUrl || "").trim();
+    const bundleImageUrlsRaw = sanitizeBundleImages(body.bundleImageUrls);
+    const [referenceImageCheck, bundleImageCheck, modelImageCheck] = await Promise.all([
+      filterReachableRemoteUrls(referenceImagesRaw, { timeoutMs: 3000 }),
+      filterReachableRemoteUrls(bundleImageUrlsRaw, { timeoutMs: 3000 }),
+      modelImageUrlRaw
+        ? filterReachableRemoteUrls([modelImageUrlRaw], { timeoutMs: 3000 })
+        : Promise.resolve({ kept: [] as string[], dropped: [] as string[] }),
+    ]);
+    const referenceImages = referenceImageCheck.kept.slice(0, 12);
+    const bundleImageUrls = bundleImageCheck.kept.slice(0, 3);
+    const modelImageUrl = modelImageCheck.kept[0] || "";
+    if (referenceImageCheck.dropped.length > 0) {
+      console.warn("[Canvas Detail Plan] Dropping unreachable referenceImages:", {
+        count: referenceImageCheck.dropped.length,
+        urls: referenceImageCheck.dropped.slice(0, 6),
+      });
+    }
+    if (bundleImageCheck.dropped.length > 0) {
+      console.warn("[Canvas Detail Plan] Dropping unreachable bundleImageUrls:", {
+        count: bundleImageCheck.dropped.length,
+        urls: bundleImageCheck.dropped.slice(0, 3),
+      });
+    }
+    if (modelImageUrlRaw && !modelImageUrl) {
+      console.warn("[Canvas Detail Plan] modelImageUrl unreachable, ignore this run:", modelImageUrlRaw);
+    }
+    const effectiveReferenceImageNotes =
+      referenceImages.length === referenceImagesRaw.length ? referenceImageNotes : [];
     const hasModelImage = /^https?:\/\//i.test(modelImageUrl);
     const hasBundleImages = bundleImageUrls.length > 0;
     const count = hasBundleImages ? Math.min(20, baseCount + 1) : baseCount;
@@ -1696,7 +1724,7 @@ export async function POST(request: Request) {
       language,
       brief,
       coreFocus,
-      referenceImageNotes,
+      referenceImageNotes: effectiveReferenceImageNotes,
       hasModelImage,
       hasBundleImages,
       bundleImageCount: bundleImageUrls.length,
@@ -1766,8 +1794,8 @@ export async function POST(request: Request) {
       `首屏标题参考（必须承接核心卖点）：${coreFocus.firstScreenTitle}`,
       "首屏命名规则：标题必须是“名字+需求一句话”（如“甩甩杆，自拍不手抖”），不能只给一个名字。",
       "命名风格要求：大白话、易记、朗朗上口，未来可直接成为用户搜索词。",
-      referenceImageNotes.length > 0
-        ? `参考图说明（按上传顺序）：${referenceImageNotes.join(" | ")}`
+      effectiveReferenceImageNotes.length > 0
+        ? `参考图说明（按上传顺序）：${effectiveReferenceImageNotes.join(" | ")}`
         : "",
       hasModelImage ? "已提供固定模特图，人物场景必须复用该模特。" : "未提供模特图。",
       hasBundleImages
diff --git a/components/canvas/CanvasWorkspace.tsx b/components/canvas/CanvasWorkspace.tsx
index 6e090fab5..32913dfd1 100644
--- a/components/canvas/CanvasWorkspace.tsx
+++ b/components/canvas/CanvasWorkspace.tsx
@@ -348,6 +348,13 @@ export function CanvasWorkspace() {
     return containerRef.current.contains(target);
   }, []);
 
+  const clearBrowserTextSelection = useCallback(() => {
+    if (typeof window === "undefined") return;
+    const selection = window.getSelection();
+    if (!selection || selection.rangeCount === 0) return;
+    selection.removeAllRanges();
+  }, []);
+
   // 处理画布点击（取消选择）
   const handleCanvasClick = useCallback((e: React.MouseEvent) => {
     if (hasBlockingDialogOpen()) return;
@@ -373,12 +380,14 @@ export function CanvasWorkspace() {
     }
 
     if (tool === "select" && e.button === 0 && !isPointOnNodeElement(e.target)) {
+      e.preventDefault();
+      clearBrowserTextSelection();
       const start = toCanvasPosition(e.clientX, e.clientY);
       setIsMarqueeSelecting(true);
       setMarqueeStart(start);
       setMarqueeEnd(start);
     }
-  }, [hasBlockingDialogOpen, isEventFromCanvasContainer, isPointOnNodeElement, toCanvasPosition, tool, viewport]);
+  }, [clearBrowserTextSelection, hasBlockingDialogOpen, isEventFromCanvasContainer, isPointOnNodeElement, toCanvasPosition, tool, viewport]);
 
   // 处理画布平移
   const handleMouseMove = useCallback((e: React.MouseEvent) => {
@@ -389,6 +398,7 @@ export function CanvasWorkspace() {
     if (!isEventFromCanvasContainer(e.target)) return;
     dragPointerRef.current = toCanvasPosition(e.clientX, e.clientY);
     if (isPanning) {
+      e.preventDefault();
       setViewport({
         x: e.clientX - panStart.x,
         y: e.clientY - panStart.y,
@@ -397,6 +407,7 @@ export function CanvasWorkspace() {
     }
 
     if (isMarqueeSelecting) {
+      e.preventDefault();
       setMarqueeEnd(toCanvasPosition(e.clientX, e.clientY));
     }
   }, [hasBlockingDialogOpen, isEventFromCanvasContainer, isMarqueeSelecting, isPanning, panStart, setViewport, toCanvasPosition]);
@@ -406,6 +417,7 @@ export function CanvasWorkspace() {
     if (e && !isEventFromCanvasContainer(e.target)) return;
     setIsPanning(false);
     setSnapGuides(null);
+    clearBrowserTextSelection();
 
     if (isMarqueeSelecting && marqueeStart && marqueeEnd) {
       const left = Math.min(marqueeStart.x, marqueeEnd.x);
@@ -440,7 +452,7 @@ export function CanvasWorkspace() {
     setIsMarqueeSelecting(false);
     setMarqueeStart(null);
     setMarqueeEnd(null);
-  }, [clearSelection, isEventFromCanvasContainer, isMarqueeSelecting, marqueeEnd, marqueeStart, nodes, selectNodes, viewport.x, viewport.y, viewport.zoom]);
+  }, [clearBrowserTextSelection, clearSelection, isEventFromCanvasContainer, isMarqueeSelecting, marqueeEnd, marqueeStart, nodes, selectNodes, viewport.x, viewport.y, viewport.zoom]);
 
   // 新增图片后自动居中展示
   const centerNodeInView = useCallback((nodeId: string) => {
diff --git a/components/canvas/nodes/ImageNode.tsx b/components/canvas/nodes/ImageNode.tsx
index 94056d75b..da69a651b 100644
--- a/components/canvas/nodes/ImageNode.tsx
+++ b/components/canvas/nodes/ImageNode.tsx
@@ -1543,21 +1543,21 @@ export function ImageNode({ node, isSelected }: ImageNodeProps) {
             )}
           </div>
         ) : data.status === 'generating' ? (
-          <div className="w-full h-full flex flex-col items-center justify-center bg-muted">
+          <div className="w-full h-full flex flex-col items-center justify-center bg-muted select-none">
             <Loader2 className="h-8 w-8 animate-spin text-primary mb-2" />
-            <span className="text-sm text-muted-foreground text-center px-3">
+            <span className="text-sm text-muted-foreground text-center px-3 select-none">
               {detailProgressLabel || "生成中..."}
             </span>
           </div>
         ) : data.status === 'failed' ? (
-          <div className="w-full h-full flex flex-col items-center justify-center bg-destructive/10">
+          <div className="w-full h-full flex flex-col items-center justify-center bg-destructive/10 select-none">
             <AlertCircle className="h-8 w-8 text-destructive mb-2" />
-            <span className="text-sm text-destructive">生成失败</span>
+            <span className="text-sm text-destructive select-none">生成失败</span>
           </div>
         ) : (
-          <div className="w-full h-full flex flex-col items-center justify-center bg-muted">
+          <div className="w-full h-full flex flex-col items-center justify-center bg-muted select-none">
             <ImagePlus className="h-8 w-8 text-muted-foreground mb-2" />
-            <span className="text-sm text-muted-foreground mb-3">点击上传图片</span>
+            <span className="text-sm text-muted-foreground mb-3 select-none">点击上传图片</span>
             {/* 隐藏的文件输入 */}
             <input
               ref={fileInputRef}
diff --git a/components/canvas/nodes/VideoNode.tsx b/components/canvas/nodes/VideoNode.tsx
index 57eb50c1e..b402309ca 100644
--- a/components/canvas/nodes/VideoNode.tsx
+++ b/components/canvas/nodes/VideoNode.tsx
@@ -210,22 +210,22 @@ export function VideoNode({ node, isSelected }: VideoNodeProps) {
           )}
         </div>
       ) : data.status === 'generating' ? (
-        <div className="w-full h-full flex flex-col items-center justify-center bg-muted">
+        <div className="w-full h-full flex flex-col items-center justify-center bg-muted select-none">
           <Loader2 className="h-8 w-8 animate-spin text-primary mb-2" />
-          <span className="text-sm text-muted-foreground">生成中...</span>
+          <span className="text-sm text-muted-foreground select-none">生成中...</span>
           {data.progress && (
-            <span className="text-xs text-muted-foreground mt-1">{data.progress}%</span>
+            <span className="text-xs text-muted-foreground mt-1 select-none">{data.progress}%</span>
           )}
         </div>
       ) : data.status === 'failed' ? (
-        <div className="w-full h-full flex flex-col items-center justify-center bg-destructive/10">
+        <div className="w-full h-full flex flex-col items-center justify-center bg-destructive/10 select-none">
           <AlertCircle className="h-8 w-8 text-destructive mb-2" />
-          <span className="text-sm text-destructive">生成失败</span>
+          <span className="text-sm text-destructive select-none">生成失败</span>
         </div>
       ) : (
-        <label className="w-full h-full flex flex-col items-center justify-center bg-muted cursor-pointer hover:bg-muted/80 transition-colors">
+        <label className="w-full h-full flex flex-col items-center justify-center bg-muted cursor-pointer hover:bg-muted/80 transition-colors select-none">
           <Video className="h-8 w-8 text-muted-foreground mb-2" />
-          <span className="text-sm text-muted-foreground">点击上传视频</span>
+          <span className="text-sm text-muted-foreground select-none">点击上传视频</span>
           <input
             type="file"
             accept="video/*"
diff --git a/lib/canvas/generate-image.ts b/lib/canvas/generate-image.ts
index b21c0283f..45f03b92f 100644
--- a/lib/canvas/generate-image.ts
+++ b/lib/canvas/generate-image.ts
@@ -5,6 +5,7 @@ import { createGeminiImage } from "@/lib/ai/providers/gemini-image";
 import { createAlibabaImage } from "@/lib/ai/providers/alibaba-image";
 import { createRuxaImage } from "@/lib/ai/providers/ruxa-image";
 import { createFalImage } from "@/lib/ai/providers/fal-image";
+import { filterReachableRemoteUrls } from "@/lib/net/url-access";
 
 export interface CanvasGenerateImageRequest {
   prompt: string;
@@ -112,15 +113,26 @@ export async function generateCanvasImage(
         .filter((url) => /^https?:\/\//i.test(url))
     )
   ).slice(0, 12);
+  const { kept: reachableReferenceImages, dropped: unreachableReferenceImages } =
+    await filterReachableRemoteUrls(normalizedReferenceImages, { timeoutMs: 3000 });
+  if (unreachableReferenceImages.length > 0) {
+    console.warn("[Canvas Generate Image] Dropping unreachable reference images:", {
+      count: unreachableReferenceImages.length,
+      urls: unreachableReferenceImages.slice(0, 6),
+    });
+  }
+  if (normalizedReferenceImages.length > 0 && reachableReferenceImages.length === 0) {
+    throw new Error("参考图片链接不可访问，请重新上传后再试");
+  }
 
   const messages = [
     {
       role: "user" as const,
       content:
-        normalizedReferenceImages.length > 0
+        reachableReferenceImages.length > 0
           ? [
               { type: "text" as const, text: prompt },
-              ...normalizedReferenceImages.map((url) => ({
+              ...reachableReferenceImages.map((url) => ({
                 type: "image_url" as const,
                 image_url: { url },
               })),
diff --git a/lib/net/url-access.ts b/lib/net/url-access.ts
new file mode 100644
index 000000000..8742a1a87
--- /dev/null
+++ b/lib/net/url-access.ts
@@ -0,0 +1,86 @@
+import "server-only";
+
+type UrlAccessOptions = {
+  timeoutMs?: number;
+};
+
+const DEFAULT_TIMEOUT_MS = 3500;
+
+function withTimeout(timeoutMs: number) {
+  const controller = new AbortController();
+  const timer = setTimeout(() => controller.abort(), timeoutMs);
+  return {
+    signal: controller.signal,
+    clear: () => clearTimeout(timer),
+  };
+}
+
+export async function isRemoteUrlReachable(
+  url: string,
+  options: UrlAccessOptions = {}
+): Promise<boolean> {
+  const target = String(url || "").trim();
+  if (!/^https?:\/\//i.test(target)) return false;
+  const timeoutMs = Math.max(800, Number(options.timeoutMs || DEFAULT_TIMEOUT_MS));
+
+  const headCtx = withTimeout(timeoutMs);
+  try {
+    const headResponse = await fetch(target, {
+      method: "HEAD",
+      redirect: "follow",
+      cache: "no-store",
+      signal: headCtx.signal,
+    });
+    if (headResponse.ok) return true;
+    if (![403, 405, 429, 500, 501, 502, 503, 504].includes(headResponse.status)) {
+      return false;
+    }
+  } catch {}
+  finally {
+    headCtx.clear();
+  }
+
+  const getCtx = withTimeout(timeoutMs);
+  try {
+    const getResponse = await fetch(target, {
+      method: "GET",
+      headers: { Range: "bytes=0-0" },
+      redirect: "follow",
+      cache: "no-store",
+      signal: getCtx.signal,
+    });
+    return getResponse.ok || getResponse.status === 206;
+  } catch {
+    return false;
+  } finally {
+    getCtx.clear();
+  }
+}
+
+export async function filterReachableRemoteUrls(
+  urls: string[],
+  options: UrlAccessOptions = {}
+): Promise<{ kept: string[]; dropped: string[] }> {
+  const unique = Array.from(
+    new Set(
+      (Array.isArray(urls) ? urls : [])
+        .map((item) => String(item || "").trim())
+        .filter((item) => /^https?:\/\//i.test(item))
+    )
+  );
+  if (unique.length === 0) {
+    return { kept: [], dropped: [] };
+  }
+
+  const checks = await Promise.all(
+    unique.map(async (url) => ({
+      url,
+      ok: await isRemoteUrlReachable(url, options),
+    }))
+  );
+
+  return {
+    kept: checks.filter((item) => item.ok).map((item) => item.url),
+    dropped: checks.filter((item) => !item.ok).map((item) => item.url),
+  };
+}