diff --git a/services/canvas/index.ts b/services/canvas/index.ts
index 21bb0e72c..feff71ada 100644
--- a/services/canvas/index.ts
+++ b/services/canvas/index.ts
@@ -47,6 +47,8 @@ interface ApiResponse<T = any> {
   data?: T;
   error?: string;
   status?: number;
+  code?: string;
+  canvasUpdatedAt?: string;
   pagination?: {
     page: number;
     limit: number;
@@ -54,6 +56,22 @@ interface ApiResponse<T = any> {
   };
 }
 
+function normalizeRevisionText(value: unknown) {
+  return String(value || "").trim();
+}
+
+function syncCanvasStoreRevisionFromUpdatedAt(updatedAt: unknown): void {
+  if (typeof window === "undefined") return;
+  const revision = normalizeRevisionText(updatedAt);
+  if (!revision) return;
+  useCanvasStore.getState().setCanvasRevision(revision, revision);
+}
+
+function syncCanvasStoreRevisionFromProject(project?: Partial<CanvasProject> | null): void {
+  if (!project?.canvasData) return;
+  syncCanvasStoreRevisionFromUpdatedAt(project.updatedAt);
+}
+
 export interface NormalizedCropRect {
   x: number;
   y: number;
@@ -147,6 +165,9 @@ export const canvasService = {
     try {
       const response = await fetch(`/api/canvas/${id}`);
       const data = await response.json();
+      if (data?.success) {
+        syncCanvasStoreRevisionFromProject(data.data);
+      }
       return data;
     } catch (error) {
       return { success: false, error: '获取画布失败' };
@@ -165,6 +186,9 @@ export const canvasService = {
         body: JSON.stringify({ ...project, workspaceType }),
       });
       const data = await response.json();
+      if (data?.success) {
+        syncCanvasStoreRevisionFromProject(data.data);
+      }
       return data;
     } catch (error) {
       return { success: false, error: '创建画布失败' };
@@ -243,8 +267,16 @@ export const canvasService = {
           success: false,
           error: String(data?.error || data?.message || '保存画布状态失败'),
           status: response.status,
+          code: typeof data?.code === "string" ? data.code : undefined,
+          canvasUpdatedAt:
+            typeof data?.canvasUpdatedAt === "string"
+              ? data.canvasUpdatedAt
+              : undefined,
         };
       }
+      if (data?.success) {
+        syncCanvasStoreRevisionFromUpdatedAt(data?.data?.updatedAt);
+      }
       return data as ApiResponse;
     } catch (error) {
       return { success: false, error: '保存画布状态失败' };
diff --git a/tests/routes/canvas-chat-helpers.test.ts b/tests/routes/canvas-chat-helpers.test.ts
index 785ab8c45..c74c5f753 100644
--- a/tests/routes/canvas-chat-helpers.test.ts
+++ b/tests/routes/canvas-chat-helpers.test.ts
@@ -514,10 +514,139 @@ test.describe("canvas chat pure helpers", () => {
       canvasData,
       workspaceType: "canvas",
       baseCanvasRevision: "2026-06-22T00:00:12.000Z",
-      baseCanvasUpdatedAt: "2026-06-22T00:00:10.000Z",
+      baseCanvasUpdatedAt: "2026-06-22T00:00:11.000Z",
     });
   });
 
+  test("canvas service keeps store revision aligned after project load and save", async () => {
+    const canvasData = {
+      nodes: [],
+      edges: [],
+      selectedNodeIds: [],
+      viewport: { x: 0, y: 0, zoom: 1 },
+      tool: "select" as const,
+    };
+    const originalFetch = globalThis.fetch;
+    const hadWindow = Object.prototype.hasOwnProperty.call(globalThis, "window");
+    const originalWindow = (globalThis as typeof globalThis & { window?: unknown })
+      .window;
+    const responses = [
+      {
+        success: true,
+        data: {
+          id: "11111111-1111-4111-8111-111111111111",
+          title: "测试画布",
+          canvasData,
+          updatedAt: "2026-06-22T00:01:00.000Z",
+        },
+      },
+      {
+        success: true,
+        data: {
+          updatedAt: "2026-06-22T00:01:05.000Z",
+        },
+      },
+    ];
+
+    useCanvasStore.getState().setCanvasRevision(null, null);
+    Object.defineProperty(globalThis, "window", {
+      configurable: true,
+      value: {},
+      writable: true,
+    });
+    globalThis.fetch = (async () =>
+      ({
+        ok: true,
+        status: 200,
+        json: async () => responses.shift()!,
+      }) as Response) as typeof fetch;
+
+    try {
+      await canvasService.getProject("11111111-1111-4111-8111-111111111111");
+      expect(useCanvasStore.getState().canvasRevision).toBe(
+        "2026-06-22T00:01:00.000Z"
+      );
+
+      await canvasService.saveCanvasState(
+        "11111111-1111-4111-8111-111111111111",
+        canvasData
+      );
+      expect(useCanvasStore.getState().canvasRevision).toBe(
+        "2026-06-22T00:01:05.000Z"
+      );
+      expect(useCanvasStore.getState().canvasUpdatedAt).toBe(
+        "2026-06-22T00:01:05.000Z"
+      );
+    } finally {
+      globalThis.fetch = originalFetch;
+      if (hadWindow) {
+        Object.defineProperty(globalThis, "window", {
+          configurable: true,
+          value: originalWindow,
+          writable: true,
+        });
+      } else {
+        Reflect.deleteProperty(globalThis, "window");
+      }
+      useCanvasStore.getState().setCanvasRevision(null, null);
+    }
+  });
+
+  test("canvas service exposes stale save conflict details", async () => {
+    const originalFetch = globalThis.fetch;
+    const hadWindow = Object.prototype.hasOwnProperty.call(globalThis, "window");
+    const originalWindow = (globalThis as typeof globalThis & { window?: unknown })
+      .window;
+
+    Object.defineProperty(globalThis, "window", {
+      configurable: true,
+      value: {},
+      writable: true,
+    });
+    globalThis.fetch = (async () =>
+      ({
+        ok: false,
+        status: 409,
+        json: async () => ({
+          success: false,
+          error: "画布已更新，请刷新后再保存",
+          code: "STALE_CANVAS_REVISION",
+          canvasUpdatedAt: "2026-06-22T00:02:00.000Z",
+        }),
+      }) as Response) as typeof fetch;
+
+    try {
+      const result = await canvasService.saveCanvasState(
+        "11111111-1111-4111-8111-111111111111",
+        {
+          nodes: [],
+          edges: [],
+          selectedNodeIds: [],
+          viewport: { x: 0, y: 0, zoom: 1 },
+          tool: "select",
+        }
+      );
+
+      expect(result).toMatchObject({
+        success: false,
+        status: 409,
+        code: "STALE_CANVAS_REVISION",
+        canvasUpdatedAt: "2026-06-22T00:02:00.000Z",
+      });
+    } finally {
+      globalThis.fetch = originalFetch;
+      if (hadWindow) {
+        Object.defineProperty(globalThis, "window", {
+          configurable: true,
+          value: originalWindow,
+          writable: true,
+        });
+      } else {
+        Reflect.deleteProperty(globalThis, "window");
+      }
+    }
+  });
+
   const plannerContext: CanvasAgentContext = {
     version: 1,
     source: "canvas",