diff --git a/api/service/stagedstreamsync/sig_verify.go b/api/service/stagedstreamsync/sig_verify.go
index dc0b4cf4c..bc204fb1a 100644
--- a/api/service/stagedstreamsync/sig_verify.go
+++ b/api/service/stagedstreamsync/sig_verify.go
@@ -29,7 +29,7 @@ func verifyAndInsertBlocks(bc blockChain, blocks types.Blocks, blockExecution bo
 	return len(blocks), nil
 }
 
-func verifyAndInsertBlock(bc blockChain, block *types.Block, blockExecution bool, nextBlocks ...*types.Block) error {
+func verifyBlock(bc blockChain, block *types.Block, nextBlocks ...*types.Block) error {
 	var (
 		sigBytes bls.SerializedSignature
 		bitmap   []byte
@@ -61,7 +61,18 @@ func verifyAndInsertBlock(bc blockChain, block *types.Block, blockExecution bool
 	case err != nil:
 		return errors.Wrap(err, "[InsertChain]")
 	default:
+	}
+	return nil
+}
 
+func verifyAndInsertBlock(bc blockChain, block *types.Block, blockExecution bool, nextBlocks ...*types.Block) error {
+	//verify block
+	if err := verifyBlock(bc, block, nextBlocks...); err != nil {
+		return err
+	}
+	// insert block
+	if _, err := bc.InsertChain(types.Blocks{block}, false, blockExecution); err != nil {
+		return errors.Wrap(err, "[InsertChain]")
 	}
 	return nil
 }