diff --git a/services/dtbschedmgr/src/distributedWant/distributed_want_params.cpp b/services/dtbschedmgr/src/distributedWant/distributed_want_params.cpp
index df2c19cb..4f6295fe 100644
--- a/services/dtbschedmgr/src/distributedWant/distributed_want_params.cpp
+++ b/services/dtbschedmgr/src/distributedWant/distributed_want_params.cpp
@@ -116,6 +116,10 @@ DistributedUnsupportedData& DistributedUnsupportedData::operator=(DistributedUns
 
 std::string DistributedWantParams::GetStringByType(const sptr<AAFwk::IInterface> iIt, int typeId)
 {
+    if (iIt == nullptr) {
+        return "";
+    }
+
     if (typeId == VALUE_TYPE_BOOLEAN) {
         return static_cast<AAFwk::Boolean*>(AAFwk::IBoolean::Query(iIt))->ToString();
     } else if (typeId == VALUE_TYPE_BYTE) {
@@ -314,6 +318,9 @@ sptr<IInterface> DistributedWantParams::GetInterfaceByType(int typeId, const std
 bool DistributedWantParams::CompareNumberInterface(const sptr<IInterface> iIt1,
     const sptr<IInterface> iIt2, int typeId)
 {
+    if (iIt1 == nullptr) {
+        return false;
+    }
     bool flag = false;
     switch (typeId) {
         case VALUE_TYPE_SHORT:
@@ -344,6 +351,9 @@ bool DistributedWantParams::CompareNumberInterface(const sptr<IInterface> iIt1,
 
 bool DistributedWantParams::CompareInterface(const sptr<IInterface> iIt1, const sptr<IInterface> iIt2, int typeId)
 {
+    if (iIt1 == nullptr) {
+        return false;
+    }
     bool flag = false;
     switch (typeId) {
         case VALUE_TYPE_BOOLEAN:
@@ -465,6 +475,9 @@ bool DistributedWantParams::WriteToParcelWantParams(Parcel& parcel, sptr<IInterf
     if (!parcel.WriteInt32(VALUE_TYPE_WANTPARAMS)) {
         return false;
     }
+    if (o == nullptr) {
+        return false;
+    }
     return parcel.WriteString16(Str8ToStr16(
         static_cast<DistributedWantParamWrapper*>(IDistributedWantParams::Query(o))->ToString()));
 }
diff --git a/services/dtbschedmgr/src/distributed_sched_service.cpp b/services/dtbschedmgr/src/distributed_sched_service.cpp
index 52f521fa..c656b3d2 100644
--- a/services/dtbschedmgr/src/distributed_sched_service.cpp
+++ b/services/dtbschedmgr/src/distributed_sched_service.cpp
@@ -1846,7 +1846,7 @@ void DistributedSchedService::ProcessCalleeOffline(const std::string& deviceId)
                 }
                 ReportDistributedComponentChange(callerInfo, DISTRIBUTED_COMPONENT_REMOVE,
                     IDistributedSched::CALL, IDistributedSched::CALLER);
-                callerMap_.erase(iter++);
+                iter = callerMap_.erase(iter);
             } else {
                 iter++;
             }
@@ -2492,7 +2492,7 @@ int32_t DistributedSchedService::NotifyProcessDiedFromRemote(const CallerInfo& c
                 }
                 ReportDistributedComponentChange(connectInfo, DISTRIBUTED_COMPONENT_REMOVE,
                     IDistributedSched::CONNECT, IDistributedSched::CALLEE);
-                connectAbilityMap_.erase(iter++);
+                iter = connectAbilityMap_.erase(iter);
             } else {
                 iter++;
             }
@@ -2525,7 +2525,7 @@ void DistributedSchedService::RemoveConnectAbilityInfo(const std::string& device
                 DecreaseConnectLocked(uid);
                 ReportDistributedComponentChange(callerInfo, DISTRIBUTED_COMPONENT_REMOVE,
                     IDistributedSched::CONNECT, IDistributedSched::CALLER);
-                distributedConnectAbilityMap_.erase(iter++);
+                iter = distributedConnectAbilityMap_.erase(iter);
             } else {
                 iter++;
             }
@@ -2656,7 +2656,7 @@ void DistributedSchedService::ProcessConnectDied(const sptr<IRemoteObject>& conn
                 }
                 ReportDistributedComponentChange(callerInfo, DISTRIBUTED_COMPONENT_REMOVE,
                     IDistributedSched::CONNECT, IDistributedSched::CALLER);
-                distributedConnectAbilityMap_.erase(iter++);
+                iter = distributedConnectAbilityMap_.erase(iter);
             } else {
                 iter++;
             }
diff --git a/services/dtbschedmgr/src/distributed_sched_stub.cpp b/services/dtbschedmgr/src/distributed_sched_stub.cpp
index 0d954e77..a916f269 100644
--- a/services/dtbschedmgr/src/distributed_sched_stub.cpp
+++ b/services/dtbschedmgr/src/distributed_sched_stub.cpp
@@ -1546,6 +1546,9 @@ int32_t DistributedSchedStub::StartFreeInstallFromRemoteInner(MessageParcel& dat
     info.want.RemoveParam(PARAM_FREEINSTALL_APPID);
     info.want.SetParam(PARAM_FREEINSTALL_APPID, callerInfo.callerAppId);
     info.want.RemoveParam(PARAM_FREEINSTALL_BUNDLENAMES);
+    if (cmpWant == nullptr) {
+        return ERR_NULL_OBJECT;
+    }
     info.want.SetParam(
         PARAM_FREEINSTALL_BUNDLENAMES, (*cmpWant).GetStringArrayParam(CMPT_PARAM_FREEINSTALL_BUNDLENAMES));
     result = StartFreeInstallFromRemote(info, taskId);
diff --git a/services/dtbschedmgr/src/dms_callback_task.cpp b/services/dtbschedmgr/src/dms_callback_task.cpp
index 9a17d9bd..6b16e6f4 100644
--- a/services/dtbschedmgr/src/dms_callback_task.cpp
+++ b/services/dtbschedmgr/src/dms_callback_task.cpp
@@ -173,7 +173,7 @@ void DmsCallbackTask::NotifyDeviceOffline(const std::string& deviceId)
                 dmsCallbackHandler_->RemoveEvent(it->second.taskId);
             }
             DistributedSchedService::GetInstance().NotifyFreeInstallResult(it->second, DEVICE_OFFLINE_ERR);
-            (void)callbackMap_.erase(it++);
+            it = callbackMap_.erase(it);
         } else {
             it++;
         }