diff --git a/source/libs/sync/inc/syncInt.h b/source/libs/sync/inc/syncInt.h
index ba7e35ec5bd773ccdbf5788a42c1f1ee3917ecf8..076526e6c9a659a85628c9a12b9d53430c7dacd3 100644
--- a/source/libs/sync/inc/syncInt.h
+++ b/source/libs/sync/inc/syncInt.h
@@ -225,6 +225,8 @@ int32_t   syncNodeGetPreIndexTerm(SSyncNode* pSyncNode, SyncIndex index, SyncInd
 
 int32_t syncNodeCommit(SSyncNode* ths, SyncIndex beginIndex, SyncIndex endIndex, uint64_t flag);
 
+bool syncNodeInRaftGroup(SSyncNode* ths, SRaftId* pRaftId);
+
 // for debug --------------
 void syncNodePrint(SSyncNode* pObj);
 void syncNodePrint2(char* s, SSyncNode* pObj);
diff --git a/source/libs/sync/src/syncAppendEntriesReply.c b/source/libs/sync/src/syncAppendEntriesReply.c
index f5bcda195517c97970febdc34a769d49b363128c..1e587dac92992be0645fd46f3d89917be51446f1 100644
--- a/source/libs/sync/src/syncAppendEntriesReply.c
+++ b/source/libs/sync/src/syncAppendEntriesReply.c
@@ -104,6 +104,12 @@ int32_t syncNodeOnAppendEntriesReplySnapshotCb(SSyncNode* ths, SyncAppendEntries
   snprintf(logBuf, sizeof(logBuf), "recv SyncAppendEntriesReply, term:%lu", ths->pRaftStore->currentTerm);
   syncAppendEntriesReplyLog2(logBuf, pMsg);
 
+  // if already drop replica, do not process
+  if (!syncNodeInRaftGroup(ths, &(pMsg->srcId))) {
+    sInfo("maybe already dropped");
+    return ret;
+  }
+
   // drop stale response
   if (pMsg->term < ths->pRaftStore->currentTerm) {
     sTrace("recv SyncAppendEntriesReply, drop stale response, receive_term:%lu current_term:%lu", pMsg->term,
@@ -162,7 +168,7 @@ int32_t syncNodeOnAppendEntriesReplySnapshotCb(SSyncNode* ths, SyncAppendEntries
         SSnapshot snapshot;
         ths->pFsm->FpGetSnapshot(ths->pFsm, &snapshot);
         if (nextIndex <= snapshot.lastApplyIndex) {
-          ASSERT(nextIndex == snapshot.lastApplyIndex);
+          // ASSERT(nextIndex == snapshot.lastApplyIndex);
 
           nextIndex = snapshot.lastApplyIndex + 1;
           sInfo("reset new nextIndex %ld, snapshot.lastApplyIndex:%ld", nextIndex, snapshot.lastApplyIndex);
diff --git a/source/libs/sync/src/syncMain.c b/source/libs/sync/src/syncMain.c
index 2aafbb1fb59290906cffd456232d600a5a64eb1d..951da64b7cca156b39d23ca5d6a1b2b38d965e55 100644
--- a/source/libs/sync/src/syncMain.c
+++ b/source/libs/sync/src/syncMain.c
@@ -1347,7 +1347,7 @@ SyncIndex syncNodeGetPreIndex(SSyncNode* pSyncNode, SyncIndex index) {
       pSyncNode->pFsm->FpGetSnapshot(pSyncNode->pFsm, &snapshot);
     }
 
-    ASSERT(index > snapshot.lastApplyIndex);
+    // ASSERT(index > snapshot.lastApplyIndex);
     preIndex = index - 1;
 
   } else {
@@ -1375,7 +1375,7 @@ SyncTerm syncNodeGetPreTerm(SSyncNode* pSyncNode, SyncIndex index) {
       pSyncNode->pFsm->FpGetSnapshot(pSyncNode->pFsm, &snapshot);
     }
 
-    ASSERT(index > snapshot.lastApplyIndex);
+    // ASSERT(index > snapshot.lastApplyIndex);
     if (index > snapshot.lastApplyIndex + 1) {
       // should be log preTerm
       SSyncRaftEntry* pPreEntry = NULL;
@@ -1389,7 +1389,9 @@ SyncTerm syncNodeGetPreTerm(SSyncNode* pSyncNode, SyncIndex index) {
     } else if (index == snapshot.lastApplyIndex + 1) {
       preTerm = snapshot.lastApplyTerm;
     } else {
-      ASSERT(0);
+      // ASSERT(0);
+      // maybe snapshot change
+      preTerm = snapshot.lastApplyTerm;
     }
 
   } else {
@@ -1799,4 +1801,13 @@ int32_t syncNodeCommit(SSyncNode* ths, SyncIndex beginIndex, SyncIndex endIndex,
     }
   }
   return 0;
+}
+
+bool syncNodeInRaftGroup(SSyncNode* ths, SRaftId* pRaftId) {
+  for (int i = 0; i < ths->replicaNum; ++i) {
+    if (syncUtilSameId(&((ths->replicasId)[i]), pRaftId)) {
+      return true;
+    }
+  }
+  return false;
 }
\ No newline at end of file