diff --git a/CHANGELOG.md b/CHANGELOG.md
index ea46080777bbab5e820039d990a05f5f1fdab9f5..3105530a4bc85b423b158125f51b6fafb90883b7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ Please mark all change in change log and use the issue from GitHub
 -   \#2637 Suit the range of HNSW parameters
 -   \#2642 Create index failed and server crashed
 -   \#2649 Search parameter of annoy has conflict with document
+-   \#2692 Milvus hangs during multi-thread concurrent search
 
 ## Feature
 
diff --git a/core/src/server/delivery/request/BaseRequest.cpp b/core/src/server/delivery/request/BaseRequest.cpp
index 65ebc05502736ad8aecf741f2348a8678e54d53e..bac0015763a56baf8cb1bb52701dd5e6d7a453ff 100644
--- a/core/src/server/delivery/request/BaseRequest.cpp
+++ b/core/src/server/delivery/request/BaseRequest.cpp
@@ -127,6 +127,7 @@ BaseRequest::OnPostExecute() {
 
 void
 BaseRequest::Done() {
+    std::unique_lock<std::mutex> lock(finish_mtx_);
     done_ = true;
     finish_cond_.notify_all();
 }
diff --git a/core/src/server/delivery/request/BaseRequest.h b/core/src/server/delivery/request/BaseRequest.h
index 7def31950e80ca01274ca0a64d1efb0de66318f9..5ed4002800a0db24b227509b8b01f3952e00c971 100644
--- a/core/src/server/delivery/request/BaseRequest.h
+++ b/core/src/server/delivery/request/BaseRequest.h
@@ -211,15 +211,16 @@ class BaseRequest {
  protected:
     const std::shared_ptr<milvus::server::Context> context_;
 
-    mutable std::mutex finish_mtx_;
-    std::condition_variable finish_cond_;
-
     RequestType type_;
     std::string request_group_;
     bool async_;
-    bool done_;
     Status status_;
 
+ private:
+    mutable std::mutex finish_mtx_;
+    std::condition_variable finish_cond_;
+    bool done_;
+
  public:
     const std::shared_ptr<milvus::server::Context>&
     Context() const {