diff --git a/apps/web/components/workbench/ChapterAssistant.tsx b/apps/web/components/workbench/ChapterAssistant.tsx
index 1935ad6..8d7ab12 100644
--- a/apps/web/components/workbench/ChapterAssistant.tsx
+++ b/apps/web/components/workbench/ChapterAssistant.tsx
@@ -1,7 +1,10 @@
 "use client";
 
 import Link from "next/link";
+import { RotateCcw, X } from "lucide-react";
 
+import { StatusNote } from "@/components/ui/StatusNote";
+import { buttonClass } from "@/lib/ui/variants";
 import {
   isPinned,
   kindLabel,
@@ -61,30 +64,69 @@ export function AssistantContent({ projectId, chapterNo }: ChapterAssistantProps
 
         {injection.loading ? (
           <p className="mt-2 text-xs text-ink-soft">加载注入信息…</p>
-        ) : injection.error ? (
-          <p className="mt-2 rounded border border-dashed border-line bg-bg p-3 text-xs text-ink-soft">
-            {injection.error}
-          </p>
-        ) : selected.length === 0 ? (
-          <p className="mt-2 rounded border border-dashed border-line bg-bg p-3 text-xs text-ink-soft">
-            本章暂无注入实体（先在大纲点名设定/角色，或从下方排除项恢复）。
-          </p>
+        ) : !data ? (
+          // 首次加载失败：data 仍为空 → 满屏错误框 + 重试。
+          <StatusNote variant="danger" className="mt-2 text-xs" title="注入信息暂不可用">
+            <p>请检查后端连接后重试。</p>
+            <button
+              type="button"
+              onClick={injection.reload}
+              className={buttonClass({ variant: "outline", size: "sm", className: "mt-2" })}
+            >
+              <RotateCcw className="h-3.5 w-3.5" aria-hidden="true" />
+              重试
+            </button>
+          </StatusNote>
         ) : (
-          <ul className="mt-2 space-y-2">
-            {selected.map((entity) => (
-              <EntityRow
-                key={`${entity.kind}:${entity.name}`}
-                entity={entity}
-                pinned={isPinned(
-                  { pinned: data?.pinned, excluded: data?.excluded, recent_n: data?.recent_n },
-                  entity,
-                )}
-                disabled={injection.saving}
-                onTogglePin={injection.togglePin}
-                onExclude={injection.exclude}
-              />
-            ))}
-          </ul>
+          <>
+            {injection.saveError ? (
+              // 保存失败：悬浮提示，不替换列表；可关闭 + 重试上一次覆盖。
+              <StatusNote variant="danger" className="mt-2 text-xs" title={injection.saveError}>
+                <div className="mt-1 flex items-center gap-2">
+                  <button
+                    type="button"
+                    onClick={() => void injection.retrySave()}
+                    disabled={injection.saving}
+                    className={buttonClass({ variant: "outline", size: "sm" })}
+                  >
+                    <RotateCcw className="h-3.5 w-3.5" aria-hidden="true" />
+                    重试
+                  </button>
+                  <button
+                    type="button"
+                    onClick={injection.clearSaveError}
+                    aria-label="关闭保存失败提示"
+                    className={buttonClass({ variant: "ghost", size: "sm" })}
+                  >
+                    <X className="h-3.5 w-3.5" aria-hidden="true" />
+                    关闭
+                  </button>
+                </div>
+              </StatusNote>
+            ) : null}
+
+            {selected.length === 0 ? (
+              <p className="mt-2 rounded border border-dashed border-line bg-bg p-3 text-xs text-ink-soft">
+                本章暂无注入实体（先在大纲点名设定/角色，或从下方排除项恢复）。
+              </p>
+            ) : (
+              <ul className="mt-2 space-y-2">
+                {selected.map((entity) => (
+                  <EntityRow
+                    key={`${entity.kind}:${entity.name}`}
+                    entity={entity}
+                    pinned={isPinned(
+                      { pinned: data.pinned, excluded: data.excluded, recent_n: data.recent_n },
+                      entity,
+                    )}
+                    disabled={injection.saving}
+                    onTogglePin={injection.togglePin}
+                    onExclude={injection.exclude}
+                  />
+                ))}
+              </ul>
+            )}
+          </>
         )}
 
         {excluded.length > 0 ? (
@@ -115,7 +157,7 @@ export function AssistantContent({ projectId, chapterNo }: ChapterAssistantProps
         </p>
         <Link
           href={`/projects/${projectId}/review?chapter=${chapterNo}`}
-          className="mt-2 inline-block rounded border border-cinnabar px-3 py-1.5 text-xs text-cinnabar hover:bg-[var(--color-cinnabar-wash)]"
+          className={buttonClass({ variant: "outline", size: "sm", className: "mt-2" })}
         >
           去审稿 →
         </Link>
diff --git a/apps/web/lib/workbench/useInjection.test.ts b/apps/web/lib/workbench/useInjection.test.ts
index fdca77a..579b045 100644
--- a/apps/web/lib/workbench/useInjection.test.ts
+++ b/apps/web/lib/workbench/useInjection.test.ts
@@ -43,7 +43,8 @@ describe("useInjection", () => {
     await waitFor(() => expect(result.current.loading).toBe(false));
 
     expect(result.current.data).toEqual(body);
-    expect(result.current.error).toBeNull();
+    expect(result.current.loadError).toBeNull();
+    expect(result.current.saveError).toBeNull();
   });
 
   it("挂载后端返回 error：给可读文案、data 置空", async () => {
@@ -52,7 +53,7 @@ describe("useInjection", () => {
     const { result } = renderHook(() => useInjection("p1", 3));
     await waitFor(() => expect(result.current.loading).toBe(false));
 
-    expect(result.current.error).toBe("注入信息暂不可用");
+    expect(result.current.loadError).toBe("注入信息暂不可用");
     expect(result.current.data).toBeNull();
   });
 
@@ -62,7 +63,7 @@ describe("useInjection", () => {
     const { result } = renderHook(() => useInjection("p1", 3));
     await waitFor(() => expect(result.current.loading).toBe(false));
 
-    expect(result.current.error).toBe("注入信息暂不可用");
+    expect(result.current.loadError).toBe("注入信息暂不可用");
     expect(result.current.data).toBeNull();
   });
 
@@ -81,7 +82,7 @@ describe("useInjection", () => {
     expect(put).toHaveBeenCalledTimes(1);
     expect(result.current.data).toEqual(updated);
     expect(result.current.saving).toBe(false);
-    expect(result.current.error).toBeNull();
+    expect(result.current.saveError).toBeNull();
   });
 
   it("exclude / restore / setRecentN 各自经 PUT 提交覆盖", async () => {
@@ -121,7 +122,7 @@ describe("useInjection", () => {
       await result.current.togglePin(CHAR);
     });
 
-    expect(result.current.error).toBe("保存注入设置失败，请重试");
+    expect(result.current.saveError).toBe("保存注入设置失败，请重试");
     expect(result.current.data).toEqual(loaded);
   });
 
@@ -137,10 +138,60 @@ describe("useInjection", () => {
       await result.current.togglePin(CHAR);
     });
 
-    expect(result.current.error).toBe("保存注入设置失败，请重试");
+    expect(result.current.saveError).toBe("保存注入设置失败，请重试");
     expect(result.current.data).toEqual(loaded);
   });
 
+  it("保存失败不清空 data，且 loadError 与 saveError 互不影响", async () => {
+    const loaded = makeResponse({ recent_n: 4 });
+    get.mockResolvedValue({ data: loaded, error: null });
+    put.mockResolvedValue({ data: null, error: { detail: "422" } });
+
+    const { result } = renderHook(() => useInjection("p1", 3));
+    await waitFor(() => expect(result.current.loading).toBe(false));
+
+    // 加载成功 → loadError 为空。
+    expect(result.current.loadError).toBeNull();
+
+    await act(async () => {
+      await result.current.togglePin(CHAR);
+    });
+
+    // 保存失败只设 saveError；data 与 loadError 不受影响。
+    expect(result.current.saveError).toBe("保存注入设置失败，请重试");
+    expect(result.current.loadError).toBeNull();
+    expect(result.current.data).toEqual(loaded);
+
+    // clearSaveError 关闭悬浮提示，data 仍在。
+    act(() => result.current.clearSaveError());
+    expect(result.current.saveError).toBeNull();
+    expect(result.current.data).toEqual(loaded);
+  });
+
+  it("retrySave 重放上一次失败的覆盖，成功后回放 data、清空 saveError", async () => {
+    const loaded = makeResponse({ recent_n: 4 });
+    get.mockResolvedValue({ data: loaded, error: null });
+    put.mockResolvedValueOnce({ data: null, error: { detail: "422" } });
+    const updated = makeResponse({ recent_n: 4, pinned: [{ ...CHAR }] });
+    put.mockResolvedValueOnce({ data: updated, error: null });
+
+    const { result } = renderHook(() => useInjection("p1", 3));
+    await waitFor(() => expect(result.current.loading).toBe(false));
+
+    await act(async () => {
+      await result.current.togglePin(CHAR);
+    });
+    expect(result.current.saveError).toBe("保存注入设置失败，请重试");
+
+    await act(async () => {
+      await result.current.retrySave();
+    });
+
+    expect(put).toHaveBeenCalledTimes(2);
+    expect(result.current.saveError).toBeNull();
+    expect(result.current.data).toEqual(updated);
+  });
+
   it("data 未就绪时 mutate 早返回、不发 PUT", async () => {
     get.mockResolvedValue({ data: null, error: { detail: "fail" } });
 
diff --git a/apps/web/lib/workbench/useInjection.ts b/apps/web/lib/workbench/useInjection.ts
index c8bfeee..79a8134 100644
--- a/apps/web/lib/workbench/useInjection.ts
+++ b/apps/web/lib/workbench/useInjection.ts
@@ -18,7 +18,12 @@ export interface UseInjection {
   data: InjectionResponse | null;
   loading: boolean;
   saving: boolean;
-  error: string | null;
+  // 首次加载失败（满屏错误框）与每次保存失败（悬浮提示）独立追踪，互不覆盖。
+  loadError: string | null;
+  saveError: string | null;
+  clearSaveError: () => void;
+  reload: () => void;
+  retrySave: () => Promise<void>;
   togglePin: (ref: InjectionEntityRef) => Promise<void>;
   exclude: (ref: InjectionEntityRef) => Promise<void>;
   restore: (ref: InjectionEntityRef) => Promise<void>;
@@ -35,14 +40,20 @@ export function useInjection(projectId: string, chapterNo: number): UseInjection
   const [data, setData] = useState<InjectionResponse | null>(null);
   const [loading, setLoading] = useState(true);
   const [saving, setSaving] = useState(false);
-  const [error, setError] = useState<string | null>(null);
+  const [loadError, setLoadError] = useState<string | null>(null);
+  const [saveError, setSaveError] = useState<string | null>(null);
+  // 重载计数：loadError「重试」自增 → 触发 effect 重新拉取（不需要把 loader 提到 effect 外）。
+  const [reloadNonce, setReloadNonce] = useState(0);
   // 并发锁：保存在途时 ref 同步置位，拦下连点/快速切换造成的乱序覆盖（state 异步不可靠）。
   const savingRef = useRef(false);
+  // 记下最近一次提交的覆盖，供 saveError「重试」重放（不重复构造 override）。
+  const lastOverrideRef = useRef<InjectionOverrideRequest | null>(null);
 
   useEffect(() => {
     let cancelled = false;
     setLoading(true);
-    setError(null);
+    setLoadError(null);
+    setSaveError(null);
 
     void (async () => {
       try {
@@ -51,7 +62,7 @@ export function useInjection(projectId: string, chapterNo: number): UseInjection
         });
         if (cancelled) return;
         if (err || !body) {
-          setError("注入信息暂不可用");
+          setLoadError("注入信息暂不可用");
           setData(null);
         } else {
           setData(body);
@@ -59,7 +70,7 @@ export function useInjection(projectId: string, chapterNo: number): UseInjection
       } catch {
         // 网络层失败（后端不可达/CORS）：openapi-fetch 直接抛而非返回 error 信封。
         if (cancelled) return;
-        setError("注入信息暂不可用");
+        setLoadError("注入信息暂不可用");
         setData(null);
       } finally {
         if (!cancelled) setLoading(false);
@@ -69,28 +80,30 @@ export function useInjection(projectId: string, chapterNo: number): UseInjection
     return () => {
       cancelled = true;
     };
-  }, [projectId, chapterNo]);
+  }, [projectId, chapterNo, reloadNonce]);
 
   const save = useCallback(
     async (override: InjectionOverrideRequest) => {
       // 已有保存在途 → 早返回（避免并发 PUT 互相覆盖、回放结果乱序）。
       if (savingRef.current) return;
+      lastOverrideRef.current = override;
       savingRef.current = true;
       setSaving(true);
-      setError(null);
+      setSaveError(null);
       try {
         const { data: body, error: err } = await api.PUT(INJECTION_PATH, {
           params: { path: { project_id: projectId, chapter_no: chapterNo } },
           body: override,
         });
         if (err || !body) {
-          setError("保存注入设置失败，请重试");
+          // 保存失败：保留已加载的 data，仅设保存态错误（天然回滚 + 可重试）。
+          setSaveError("保存注入设置失败，请重试");
         } else {
           setData(body); // 以服务端确定结果为准（不变量 #6）。
         }
       } catch {
         // 网络层失败：本地状态不动（天然回滚），给可读文案、不抛。
-        setError("保存注入设置失败，请重试");
+        setSaveError("保存注入设置失败，请重试");
       } finally {
         savingRef.current = false;
         setSaving(false);
@@ -124,6 +137,26 @@ export function useInjection(projectId: string, chapterNo: number): UseInjection
     (n: number) => mutate((o) => withRecentN(o, n))(),
     [mutate],
   );
+  const clearSaveError = useCallback(() => setSaveError(null), []);
+  const reload = useCallback(() => setReloadNonce((n) => n + 1), []);
+  const retrySave = useCallback(async () => {
+    const override = lastOverrideRef.current;
+    if (!override) return;
+    await save(override);
+  }, [save]);
 
-  return { data, loading, saving, error, togglePin, exclude, restore, setRecentN };
+  return {
+    data,
+    loading,
+    saving,
+    loadError,
+    saveError,
+    clearSaveError,
+    reload,
+    retrySave,
+    togglePin,
+    exclude,
+    restore,
+    setRecentN,
+  };
 }