diff --git a/cpp/CHANGELOG.md b/cpp/CHANGELOG.md
index b50a7e90fcc4c88f611eed34a0efeffdc5054bfa..3d87261868e5af6b15fa0f70126f2934328d1bd6 100644
--- a/cpp/CHANGELOG.md
+++ b/cpp/CHANGELOG.md
@@ -92,6 +92,7 @@ Please mark all change in change log and use the ticket from JIRA.
 - MS-487 - Define metric type in CreateTable
 - MS-488 - Improve code format in scheduler
 - MS-495 - cmake: integrated knowhere
+- MS-496 - Change the top_k limitation from 1024 to 2048
 - MS-505 - Install core unit test and add to coverage
 
 ## New Feature
diff --git a/cpp/src/utils/ValidationUtil.cpp b/cpp/src/utils/ValidationUtil.cpp
index f12d68b36402583be0ed94ffec902806ca41f680..bce8143c1a4045a5b4c4ca2e0a467daf76d82e8c 100644
--- a/cpp/src/utils/ValidationUtil.cpp
+++ b/cpp/src/utils/ValidationUtil.cpp
@@ -94,7 +94,7 @@ ValidationUtil::ValidateTableIndexMetricType(int32_t metric_type) {
 
 ErrorCode
 ValidationUtil::ValidateSearchTopk(int64_t top_k, const engine::meta::TableSchema& table_schema) {
-    if (top_k <= 0 || top_k > 1024) {
+    if (top_k <= 0 || top_k > 2048) {
         return SERVER_INVALID_TOPK;
     }
 
diff --git a/cpp/src/wrapper/knowhere/vec_index.cpp b/cpp/src/wrapper/knowhere/vec_index.cpp
index e14496884de959f7198febc684b5e3ece3da01d4..1ee8697d64a97da5b316657cad96b8814365831e 100644
--- a/cpp/src/wrapper/knowhere/vec_index.cpp
+++ b/cpp/src/wrapper/knowhere/vec_index.cpp
@@ -14,6 +14,8 @@
 #include "vec_impl.h"
 #include "wrapper_log.h"
 
+#include <cuda.h>
+
 
 namespace zilliz {
 namespace milvus {
@@ -246,11 +248,13 @@ void ParameterValidation(const IndexType &type, Config &cfg) {
         case IndexType::FAISS_IVFSQ8_GPU:
         case IndexType::FAISS_IVFFLAT_GPU:
         case IndexType::FAISS_IVFPQ_GPU: {
+            //search on GPU
             if (cfg.get_with_default("nprobe", 0) != 0) {
                 auto nprobe = cfg["nprobe"].as<int>();
                 if (nprobe > GPU_MAX_NRPOBE) {
-                    WRAPPER_LOG_WARNING << "When search with GPU, nprobe shoud be no more than " << GPU_MAX_NRPOBE << ", but you passed " << nprobe
-                                      << ". Search with " << GPU_MAX_NRPOBE << " instead";
+                    WRAPPER_LOG_WARNING << "When search with GPU, nprobe shoud be no more than " << GPU_MAX_NRPOBE
+                                        << ", but you passed " << nprobe
+                                        << ". Search with " << GPU_MAX_NRPOBE << " instead";
                     cfg.insert_or_assign("nprobe", GPU_MAX_NRPOBE);
                 }
             }
diff --git a/cpp/src/wrapper/knowhere/vec_index.h b/cpp/src/wrapper/knowhere/vec_index.h
index 137429d1ad5168345cac1c1345f84392988a38ae..a5cdcabf04a836d6c8f9a6e4970c671cc5da5e66 100644
--- a/cpp/src/wrapper/knowhere/vec_index.h
+++ b/cpp/src/wrapper/knowhere/vec_index.h
@@ -14,8 +14,6 @@
 #include "knowhere/common/config.h"
 #include "knowhere/common/binary_set.h"
 
-#include "cuda.h"
-
 
 namespace zilliz {
 namespace milvus {
@@ -62,7 +60,7 @@ class VecIndex {
                              long *ids,
                              const Config &cfg = Config()) = 0;
 
-    virtual VecIndexPtr CopyToGpu(const int64_t& device_id,
+    virtual VecIndexPtr CopyToGpu(const int64_t &device_id,
                                   const Config &cfg = Config()) = 0;
 
     virtual VecIndexPtr CopyToCpu(const Config &cfg = Config()) = 0;
@@ -86,16 +84,16 @@ extern ErrorCode write_index(VecIndexPtr index, const std::string &location);
 
 extern VecIndexPtr read_index(const std::string &location);
 
-extern VecIndexPtr GetVecIndexFactory(const IndexType &type, const Config& cfg = Config());
+extern VecIndexPtr GetVecIndexFactory(const IndexType &type, const Config &cfg = Config());
 
 extern VecIndexPtr LoadVecIndex(const IndexType &index_type, const zilliz::knowhere::BinarySet &index_binary);
 
-extern void AutoGenParams(const IndexType& type, const long& size, Config& cfg);
+extern void AutoGenParams(const IndexType &type, const long &size, Config &cfg);
 
-extern void ParameterValidation(const IndexType& type, Config& cfg);
+extern void ParameterValidation(const IndexType &type, Config &cfg);
 
-extern IndexType ConvertToCpuIndexType(const IndexType& type);
-extern IndexType ConvertToGpuIndexType(const IndexType& type);
+extern IndexType ConvertToCpuIndexType(const IndexType &type);
+extern IndexType ConvertToGpuIndexType(const IndexType &type);
 
 }
 }