diff --git a/.changeset/ninety-zoos-think.md b/.changeset/ninety-zoos-think.md
new file mode 100644
index 0000000000..d3f3fcf5f2
--- /dev/null
+++ b/.changeset/ninety-zoos-think.md
@@ -0,0 +1,5 @@
+---
+"@scow/grpc-api": patch
+---
+
+当 mis-server 正在进行一次封锁状态同步时，调用 server/AdminService.UpdateBlockStatus API 会抛出`AlreadyExists`错误
diff --git a/.changeset/shaggy-maps-hunt.md b/.changeset/shaggy-maps-hunt.md
new file mode 100644
index 0000000000..579d126130
--- /dev/null
+++ b/.changeset/shaggy-maps-hunt.md
@@ -0,0 +1,6 @@
+---
+"@scow/mis-server": patch
+"@scow/mis-web": patch
+---
+
+mis-server 启动时，不完整运行一次封锁状态同步
diff --git a/apps/mis-server/config/mis.yaml b/apps/mis-server/config/mis.yaml
index 447e40e0af..57bcb626e3 100644
--- a/apps/mis-server/config/mis.yaml
+++ b/apps/mis-server/config/mis.yaml
@@ -5,4 +5,7 @@ db:
   password: mysqlrootpassword
   dbName: scow_server_${JEST_WORKER_ID}
 
+periodicSyncUserAccountBlockStatus:
+  enabled: false
+
 
diff --git a/apps/mis-server/src/app.ts b/apps/mis-server/src/app.ts
index 70e73939c7..585935b408 100644
--- a/apps/mis-server/src/app.ts
+++ b/apps/mis-server/src/app.ts
@@ -55,7 +55,5 @@ export async function createServer() {
   await server.register(misConfigServiceServer);
   await server.register(exportServiceServer);
 
-  await server.ext.syncBlockStatus.sync();
-
   return server;
 }
diff --git a/apps/mis-server/src/plugins/syncBlockStatus.ts b/apps/mis-server/src/plugins/syncBlockStatus.ts
index 7680c20294..3cba708281 100644
--- a/apps/mis-server/src/plugins/syncBlockStatus.ts
+++ b/apps/mis-server/src/plugins/syncBlockStatus.ts
@@ -23,24 +23,35 @@ export interface SyncBlockStatusPlugin {
     stop: () => void;
     schedule: string;
     lastSyncTime: () => Date | null;
-    sync: () => Promise<SyncBlockStatusResponse>;
+    run: () => Promise<SyncBlockStatusResponse | undefined>;
   }
 }
 
 export const syncBlockStatusPlugin = plugin(async (f) => {
   const synchronizeCron = misConfig.periodicSyncUserAccountBlockStatus?.cron ?? "0 4 * * *";
-  let synchronizeStarted = !!misConfig.periodicSyncUserAccountBlockStatus?.enabled;
+  let synchronizeEnabled = !!misConfig.periodicSyncUserAccountBlockStatus?.enabled;
   let synchronizeIsRunning = false;
 
   const logger = f.logger.child({ plugin: "syncBlockStatus" });
   logger.info("misConfig.periodicSyncStatus?.cron: %s", misConfig.periodicSyncUserAccountBlockStatus?.cron);
 
-  const trigger = () => {
-    if (synchronizeIsRunning) return;
+  const trigger = async () => {
+
+    const sublogger = logger.child({ time: new Date() });
+
+    if (synchronizeIsRunning) {
+      sublogger.info("Sync is already running.");
+      return Promise.resolve(undefined);
+    }
 
     synchronizeIsRunning = true;
-    return synchronizeBlockStatus(f.ext.orm.em.fork(), logger, f.ext)
-      .finally(() => { synchronizeIsRunning = false; });
+    sublogger.info("Sync starts to run.");
+
+    try {
+      return await synchronizeBlockStatus(f.ext.orm.em.fork(), sublogger, f.ext);
+    } finally {
+      synchronizeIsRunning = false;
+    }
   };
 
   const task = cron.schedule(
@@ -48,7 +59,7 @@ export const syncBlockStatusPlugin = plugin(async (f) => {
     () => { void trigger(); },
     {
       timezone: "Asia/Shanghai",
-      scheduled: misConfig.periodicSyncUserAccountBlockStatus?.enabled,
+      scheduled: synchronizeEnabled,
     },
   );
 
@@ -60,27 +71,26 @@ export const syncBlockStatusPlugin = plugin(async (f) => {
   });
 
   f.addExtension("syncBlockStatus", ({
-    started: () => synchronizeStarted,
+    started: () => synchronizeEnabled,
     start: () => {
-      if (synchronizeStarted) {
-        logger.info("Sync is requested to start but already started");
-      } else {
-        task.start();
-        synchronizeStarted = true;
-        logger.info("Sync started");
-      }
+      logger.info("Sync is started");
+      synchronizeEnabled = true;
+      task.start();
     },
     stop: () => {
-      if (!synchronizeStarted) {
-        logger.info("Sync is requested to stop but already stopped");
-      } else {
-        task.stop();
-        synchronizeStarted = false;
-        logger.info("Sync stopped");
-      }
+      logger.info("Sync is started");
+      synchronizeEnabled = false;
+      task.stop();
     },
     schedule: synchronizeCron,
     lastSyncTime: () => lastSyncTime,
-    sync: trigger,
-  } as SyncBlockStatusPlugin["syncBlockStatus"]));
+    run: trigger,
+  } satisfies SyncBlockStatusPlugin["syncBlockStatus"]));
+
+  if (synchronizeEnabled) {
+    logger.info("Started a new synchronization");
+    void trigger();
+  } else {
+    logger.info("Account/Account block sychronization is disabled.");
+  }
 });
diff --git a/apps/mis-server/src/services/admin.ts b/apps/mis-server/src/services/admin.ts
index 10863ae754..6ba7611a9a 100644
--- a/apps/mis-server/src/services/admin.ts
+++ b/apps/mis-server/src/services/admin.ts
@@ -11,8 +11,8 @@
  */
 
 import { asyncClientCall } from "@ddadaal/tsgrpc-client";
+import { ServiceError } from "@ddadaal/tsgrpc-common";
 import { plugin } from "@ddadaal/tsgrpc-server";
-import { ServiceError } from "@grpc/grpc-js";
 import { Status } from "@grpc/grpc-js/build/src/constants";
 import { libCheckActivatedClusters } from "@scow/lib-server/build/misCommon/clustersActivation";
 import {
@@ -230,7 +230,13 @@ export const adminServiceServer = plugin((server) => {
       // check whether there is activated cluster in SCOW
       // cause syncBlockStatus in plugin will skip the check
       await getActivatedClusters(em, logger);
-      const reply = await server.ext.syncBlockStatus.sync();
+      const reply = await server.ext.syncBlockStatus.run();
+      if (!reply) {
+        throw new ServiceError({
+          code: Status.ALREADY_EXISTS,
+          message: "Sync is already running. Please wait for its completion before starting a new one.",
+        });
+      }
       return [reply];
     },
 
diff --git a/apps/mis-server/tests/admin/updateBlockStatus.test.ts b/apps/mis-server/tests/admin/updateBlockStatus.test.ts
index 5bfd828db4..87a1980ed7 100644
--- a/apps/mis-server/tests/admin/updateBlockStatus.test.ts
+++ b/apps/mis-server/tests/admin/updateBlockStatus.test.ts
@@ -41,7 +41,8 @@ afterEach(async () => {
   await server.close();
 });
 
-it("test whether the block update time exists at startup", async () => {
+// Test server will not sync block status at startup
+it.skip("test whether the block update time exists at startup", async () => {
   const em = server.ext.orm.em.fork();
   const updateTime = await em.findOne(SystemState, { key: SystemState.KEYS.UPDATE_SLURM_BLOCK_STATUS });
   expect(updateTime).not.toBeNull();
diff --git a/apps/mis-web/src/i18n/en.ts b/apps/mis-web/src/i18n/en.ts
index 3ba42e53df..68051b7652 100644
--- a/apps/mis-web/src/i18n/en.ts
+++ b/apps/mis-web/src/i18n/en.ts
@@ -1003,6 +1003,8 @@ export default {
           alertInfo: "SCOW will regularly synchronize the blocking status of accounts and users to the scheduler. "
           + "You can click Sync Now to perform a manual synchronization.",
           periodicSyncUserAccountBlockStatusInfo: "Periodically Synchronize Scheduler Account And User Blocked Status",
+          syncAlreadyStarted:
+            "Synchronization is already started. Please wait for its completion before starting a new run.",
           turnedOn: "Turned On",
           paused: "Paused",
           stopSync: "Stop Synchronization",
diff --git a/apps/mis-web/src/i18n/zh_cn.ts b/apps/mis-web/src/i18n/zh_cn.ts
index 9fbae2b54d..4c2b146483 100644
--- a/apps/mis-web/src/i18n/zh_cn.ts
+++ b/apps/mis-web/src/i18n/zh_cn.ts
@@ -1001,7 +1001,7 @@ export default {
         slurmBlockStatus: {
           syncUserAccountBlockingStatus: "用户账户封锁状态同步",
           alertInfo: "SCOW会定期向调度器同步SCOW数据库中账户和用户的封锁状态，您可以点击立刻同步执行一次手动同步",
-
+          syncAlreadyStarted: "正在进行一次同步。请等待本次同步执行完成后，再重新同步。",
           periodicSyncUserAccountBlockStatusInfo:"周期性同步调度器账户和用户的封锁状态",
           turnedOn: "已开启",
           paused: "已暂停",
diff --git a/apps/mis-web/src/pages/admin/systemDebug/slurmBlockStatus.tsx b/apps/mis-web/src/pages/admin/systemDebug/slurmBlockStatus.tsx
index 24b86ac7fb..0cb7dd64da 100644
--- a/apps/mis-web/src/pages/admin/systemDebug/slurmBlockStatus.tsx
+++ b/apps/mis-web/src/pages/admin/systemDebug/slurmBlockStatus.tsx
@@ -91,6 +91,9 @@ export const SlurmBlockStatusPage: NextPage = requireAuth((u) => u.platformRoles
                       onClick={() => {
                         setFetching(true);
                         api.syncBlockStatus({})
+                          .httpError(409, () => {
+                            message.error(t(p("syncAlreadyStarted")));
+                          })
                           .then(({ blockedFailedAccounts, unblockedFailedAccounts, blockedFailedUserAccounts }) => {
                             if (!(blockedFailedAccounts.length || unblockedFailedAccounts.length
                               || blockedFailedUserAccounts.length)) {
diff --git a/apps/mis-web/src/pages/api/admin/synchronize/syncBlockStatus.ts b/apps/mis-web/src/pages/api/admin/synchronize/syncBlockStatus.ts
index 30b90afc77..c183f3e351 100644
--- a/apps/mis-web/src/pages/api/admin/synchronize/syncBlockStatus.ts
+++ b/apps/mis-web/src/pages/api/admin/synchronize/syncBlockStatus.ts
@@ -12,12 +12,14 @@
 
 import { typeboxRouteSchema } from "@ddadaal/next-typed-api-routes-runtime";
 import { asyncClientCall } from "@ddadaal/tsgrpc-client";
+import { status } from "@grpc/grpc-js";
 import { AdminServiceClient } from "@scow/protos/build/server/admin";
 import { Type } from "@sinclair/typebox";
 import { authenticate } from "src/auth/server";
 import { PlatformRole } from "src/models/User";
 import { getClient } from "src/utils/client";
 import { route } from "src/utils/route";
+import { handlegRPCError } from "src/utils/server";
 
 export const SyncBlockStatusSchema = typeboxRouteSchema({
   method: "PUT",
@@ -31,6 +33,7 @@ export const SyncBlockStatusSchema = typeboxRouteSchema({
       })),
       unblockedFailedAccounts:  Type.Array(Type.String()),
     }),
+    409: Type.Null(),
   },
 });
 const auth = authenticate((info) => info.platformRoles.includes(PlatformRole.PLATFORM_ADMIN));
@@ -43,6 +46,10 @@ export default route(SyncBlockStatusSchema,
 
     const client = getClient(AdminServiceClient);
 
-    return await asyncClientCall(client, "syncBlockStatus", {}).then((x) => ({ 200: x }));
+    return await asyncClientCall(client, "syncBlockStatus", {})
+      .then((x) => ({ 200: x }))
+      .catch(handlegRPCError({
+        [status.ALREADY_EXISTS]: () => ({ 409: null }),
+      }));
 
   });
diff --git a/protos/server/admin.proto b/protos/server/admin.proto
index 1058d88397..1344430bdd 100644
--- a/protos/server/admin.proto
+++ b/protos/server/admin.proto
@@ -193,6 +193,11 @@ service AdminService {
   rpc GetFetchInfo(GetFetchInfoRequest) returns (GetFetchInfoResponse);
   rpc SetFetchState(SetFetchStateRequest) returns (SetFetchStateResponse);
   rpc FetchJobs(FetchJobsRequest) returns (FetchJobsResponse);
+
+  /*
+   * Synchronize block status of account and account user to the backing scheduler
+   * If the synchronization is already running when the API is called, it throws ALREADY_EXISTS
+   */
   rpc UpdateBlockStatus(UpdateBlockStatusRequest)
     returns (UpdateBlockStatusResponse);
   rpc GetAdminInfo(GetAdminInfoRequest) returns (GetAdminInfoResponse) {