diff --git a/framework/src/main/java/org/tron/core/db/Manager.java b/framework/src/main/java/org/tron/core/db/Manager.java
index b1127029b46..e7aadc7f4aa 100644
--- a/framework/src/main/java/org/tron/core/db/Manager.java
+++ b/framework/src/main/java/org/tron/core/db/Manager.java
@@ -193,7 +193,8 @@ public class Manager {
   @Getter
   @Setter
   private boolean isSyncMode;
-
+  @Getter
+  private Object forkLock = new Object();
   // map<Long, IncrementalMerkleTree>
   @Getter
   @Setter
@@ -1269,8 +1270,9 @@ public void pushBlock(final BlockCapsule block)
                   chainBaseManager.getDynamicPropertiesStore().getLatestBlockHeaderTimestamp(),
                   khaosDb.getHead(), khaosDb.getMiniStore().size(),
                   khaosDb.getMiniUnlinkedStore().size());
-
-              switchFork(newBlock);
+              synchronized (forkLock) {
+                switchFork(newBlock);
+              }
               logger.info(SAVE_BLOCK, newBlock);
 
               logger.warn(
diff --git a/framework/src/main/java/org/tron/core/net/TronNetDelegate.java b/framework/src/main/java/org/tron/core/net/TronNetDelegate.java
index 7ff02250eb5..47e13de6109 100644
--- a/framework/src/main/java/org/tron/core/net/TronNetDelegate.java
+++ b/framework/src/main/java/org/tron/core/net/TronNetDelegate.java
@@ -349,4 +349,8 @@ public boolean allowPBFT() {
     return chainBaseManager.getDynamicPropertiesStore().allowPBFT();
   }
 
+  public Object getForkLock() {
+    return dbManager.getForkLock();
+  }
+
 }
diff --git a/framework/src/main/java/org/tron/core/net/service/sync/SyncService.java b/framework/src/main/java/org/tron/core/net/service/sync/SyncService.java
index 86b775df6f8..5f7ab11f6c9 100644
--- a/framework/src/main/java/org/tron/core/net/service/sync/SyncService.java
+++ b/framework/src/main/java/org/tron/core/net/service/sync/SyncService.java
@@ -23,7 +23,6 @@
 import org.tron.core.capsule.BlockCapsule.BlockId;
 import org.tron.core.config.Parameter.NetConstants;
 import org.tron.core.config.args.Args;
-import org.tron.core.exception.BadBlockException;
 import org.tron.core.exception.P2pException;
 import org.tron.core.exception.P2pException.TypeEnum;
 import org.tron.core.net.TronNetDelegate;
@@ -114,7 +113,10 @@ public void syncNext(PeerConnection peer) {
         logger.warn("Peer {} is in sync", peer.getInetSocketAddress());
         return;
       }
-      LinkedList<BlockId> chainSummary = getBlockChainSummary(peer);
+      LinkedList<BlockId> chainSummary;
+      synchronized (tronNetDelegate.getForkLock()) {
+        chainSummary = getBlockChainSummary(peer);
+      }
       peer.setSyncChainRequested(new Pair<>(chainSummary, System.currentTimeMillis()));
       peer.sendMessage(new SyncBlockChainMessage(chainSummary));
     } catch (Exception e) {