diff --git a/services/distributeddataservice/service/object/src/object_manager.cpp b/services/distributeddataservice/service/object/src/object_manager.cpp
index 859de7085d019a26f19bc35140329b36d32a3760..7d9d732135acc8eb34a51f86495181a3e1854aa4 100644
--- a/services/distributeddataservice/service/object/src/object_manager.cpp
+++ b/services/distributeddataservice/service/object/src/object_manager.cpp
@@ -438,6 +438,11 @@ void ObjectStoreManager::NotifyChange(const ObjectRecord &changedData)
         for (const auto &[key, value] : changedData) {
             keys.emplace_back(key.begin(), key.end());
         }
+        std::lock_guard<std::recursive_mutex> lock(kvStoreMutex_);
+        if (delegate_ == nullptr) {
+            ZLOGE("delegate_ is nullptr");
+            return Close();
+        }
         status = delegate_->DeleteBatch(keys);
         if (status != DistributedDB::DBStatus::OK) {
             ZLOGE("Delete entries failed, bundleName:%{public}s, source device::%{public}s, status: %{public}d",
@@ -836,6 +841,11 @@ void ObjectStoreManager::FlushClosedStore()
 void ObjectStoreManager::ProcessOldEntry(const std::string &appId)
 {
     std::vector<DistributedDB::Entry> entries;
+    std::lock_guard<std::recursive_mutex> lock(kvStoreMutex_);
+    if (delegate_ == nullptr) {
+        ZLOGE("delegate_ is nullptr");
+        return;
+    }
     auto status = delegate_->GetEntries(std::vector<uint8_t>(appId.begin(), appId.end()), entries);
     if (status == DistributedDB::DBStatus::NOT_FOUND) {
         ZLOGI("Get old entries empty, bundleName: %{public}s", appId.c_str());
@@ -898,6 +908,11 @@ int32_t ObjectStoreManager::SaveToStore(const std::string &appId, const std::str
         entry.value = item.second;
         entries.emplace_back(entry);
     }
+    std::lock_guard<std::recursive_mutex> lock(kvStoreMutex_);
+    if (delegate_ == nullptr) {
+        ZLOGE("delegate_ is nullptr");
+        return OBJECT_DBSTATUS_ERROR;
+    }
     auto status = delegate_->PutBatch(entries);
     if (status != DistributedDB::DBStatus::OK) {
         ZLOGE("PutBatch failed, bundleName: %{public}s, sessionId: %{public}s, dstNetworkId: %{public}s, "
@@ -934,6 +949,11 @@ int32_t ObjectStoreManager::SyncOnStore(
     DistributedDB::Query dbQuery = DistributedDB::Query::Select();
     dbQuery.PrefixKey(std::vector<uint8_t>(prefix.begin(), prefix.end()));
     ZLOGI("Start sync data, sequenceId: 0x%{public}" PRIx64 "", sequenceId);
+    std::lock_guard<std::recursive_mutex> lock(kvStoreMutex_);
+    if (delegate_ == nullptr) {
+        ZLOGE("delegate_ is nullptr");
+        return OBJECT_DBSTATUS_ERROR;
+    }
     auto status = delegate_->Sync(syncDevices, DistributedDB::SyncMode::SYNC_MODE_PUSH_ONLY,
         [this, sequenceId](const std::map<std::string, DistributedDB::DBStatus> &devicesMap) {
             ZLOGI("Sync data finished, sequenceId: 0x%{public}" PRIx64 "", sequenceId);
@@ -964,6 +984,11 @@ int32_t ObjectStoreManager::SetSyncStatus(bool status)
 int32_t ObjectStoreManager::RevokeSaveToStore(const std::string &prefix)
 {
     std::vector<DistributedDB::Entry> entries;
+    std::lock_guard<std::recursive_mutex> lock(kvStoreMutex_);
+    if (delegate_ == nullptr) {
+        ZLOGE("delegate_ is nullptr");
+        return OBJECT_DBSTATUS_ERROR;
+    }
     auto status = delegate_->GetEntries(std::vector<uint8_t>(prefix.begin(), prefix.end()), entries);
     if (status == DistributedDB::DBStatus::NOT_FOUND) {
         ZLOGI("Get entries empty, prefix: %{public}s", Anonymous::Change(prefix).c_str());
@@ -996,6 +1021,11 @@ int32_t ObjectStoreManager::RetrieveFromStore(const std::string &appId, const st
 {
     std::vector<DistributedDB::Entry> entries;
     std::string prefix = GetPrefixWithoutDeviceId(appId, sessionId);
+    std::lock_guard<std::recursive_mutex> lock(kvStoreMutex_);
+    if (delegate_ == nullptr) {
+        ZLOGE("delegate_ is nullptr");
+        return OBJECT_DBSTATUS_ERROR;
+    }
     auto status = delegate_->GetEntries(std::vector<uint8_t>(prefix.begin(), prefix.end()), entries);
     if (status == DistributedDB::DBStatus::NOT_FOUND) {
         ZLOGI("Get entries empty, prefix: %{public}s, status: %{public}d", prefix.c_str(), status);