diff --git a/common/utils/include/distributed_hardware_errno.h b/common/utils/include/distributed_hardware_errno.h
index 2bab94971f8c7c74dbaab52cd959ee6a539b6d1c..ffc05fd2b19cf2a052b190bca3da1a7f11ec6420 100644
--- a/common/utils/include/distributed_hardware_errno.h
+++ b/common/utils/include/distributed_hardware_errno.h
@@ -82,6 +82,7 @@ namespace DistributedHardware {
     constexpr int32_t ERR_DH_FWK_SERVICE_STRING_IS_EMPTY = -10803;
     constexpr int32_t ERR_DH_FWK_SERVICE_LOCAL_VERSION_NOT_EXIST = -10804;
     constexpr int32_t ERR_DH_FWK_SERVICE_WRITE_TOKEN_FAIL = -10805;
+    constexpr int32_t ERR_DH_FWK_SERVICE_REMOTE_IS_NULL = -10806;
 
     /* AccessManager errno, range: [-10900, -10999] */
     constexpr int32_t ERR_DH_FWK_ACCESS_INIT_DM_FAILED = -10900;
diff --git a/services/distributedhardwarefwkserviceimpl/include/resourcemanager/capability_utils.h b/services/distributedhardwarefwkserviceimpl/include/resourcemanager/capability_utils.h
index 03ba810c7ce1f1d1fe84266c25a4c4e6c577a1bc..f6e390853a5b8393b89406a727dff6b64aaaf963 100644
--- a/services/distributedhardwarefwkserviceimpl/include/resourcemanager/capability_utils.h
+++ b/services/distributedhardwarefwkserviceimpl/include/resourcemanager/capability_utils.h
@@ -23,7 +23,7 @@
 
 namespace OHOS {
 namespace DistributedHardware {
-enum CapabilityInfoFilter : uint32_t {
+enum class CapabilityInfoFilter : uint32_t {
     FILTER_DH_ID = 0,
     FILTER_DEVICE_ID = 1,
     FILTER_DEVICE_NAME = 2,
diff --git a/services/distributedhardwarefwkserviceimpl/src/componentloader/component_loader.cpp b/services/distributedhardwarefwkserviceimpl/src/componentloader/component_loader.cpp
index 10d940b1ee6e098e32096fcc16514debb397d084..604f5dd64edff02f46dc9d2198cd877f29f88880 100644
--- a/services/distributedhardwarefwkserviceimpl/src/componentloader/component_loader.cpp
+++ b/services/distributedhardwarefwkserviceimpl/src/componentloader/component_loader.cpp
@@ -131,7 +131,7 @@ void *ComponentLoader::GetHandler(const std::string &soName)
         return nullptr;
     }
     char path[PATH_MAX + 1] = {0x00};
-    if (soName.length() == 0 || soName.length() > PATH_MAX || realpath(soName.c_str(), path) == NULL) {
+    if (soName.length() == 0 || soName.length() > PATH_MAX || realpath(soName.c_str(), path) == nullptr) {
         DHLOGE("File canonicalization failed");
         return nullptr;
     }
diff --git a/services/distributedhardwarefwkserviceimpl/src/distributed_hardware_proxy.cpp b/services/distributedhardwarefwkserviceimpl/src/distributed_hardware_proxy.cpp
index 72867751c7be97b7fb2bd5956523ed50cdb49a73..0ecce1d2931a211267e520df6eaba105368d1d56 100644
--- a/services/distributedhardwarefwkserviceimpl/src/distributed_hardware_proxy.cpp
+++ b/services/distributedhardwarefwkserviceimpl/src/distributed_hardware_proxy.cpp
@@ -43,7 +43,12 @@ int32_t DistributedHardwareProxy::QuerySinkVersion(std::unordered_map<DHType, st
         DHLOGE("WriteInterfaceToken fail!");
         return ERR_DH_FWK_SERVICE_WRITE_TOKEN_FAIL;
     }
-    int32_t error = Remote()->SendRequest(QUERY_SINK_VERSION, data, reply, option);
+    sptr<IRemoteObject> remote = Remote();
+    if (remote == nullptr) {
+        DHLOGE("remote service is null");
+        return ERR_DH_FWK_SERVICE_REMOTE_IS_NULL;
+    }
+    int32_t error = remote->SendRequest(QUERY_SINK_VERSION, data, reply, option);
     if (error != NO_ERROR) {
         DHLOGE("SendRequest failed, errCode =  %d", error);
         return ERR_DH_FWK_SERVICE_IPC_SEND_REQUEST_FAIL;