diff --git a/gas-oracle/oracle/gas_price_oracle.go b/gas-oracle/oracle/gas_price_oracle.go
index dfa88d3d3..2a470eaf7 100644
--- a/gas-oracle/oracle/gas_price_oracle.go
+++ b/gas-oracle/oracle/gas_price_oracle.go
@@ -206,7 +206,7 @@ func (g *GasPriceOracle) OverHeadLoop() {
 	db, height := readGasOracleSyncHeight()
 	log.Info("ReadGasOracleSyncHeight", "height", height)
 	// set channel
-	stateBatchAppendChan := make(chan *bindings.StateCommitmentChainStateBatchAppended, 10)
+	stateBatchAppendChan := make(chan *bindings.StateCommitmentChainStateBatchAppended, 1)
 
 	// set context
 	ctcTotalBatches, err := g.ctcBackend.GetTotalBatches(&bind.CallOpts{})
@@ -247,7 +247,10 @@ func (g *GasPriceOracle) OverHeadLoop() {
 				case stateBatchAppendChan <- iter.Event:
 					log.Info("write event into channel", "channel length is", len(stateBatchAppendChan))
 				default:
-					log.Error("write too many event into channel, increase channel length")
+					// discard additional event to process the last one
+					<-stateBatchAppendChan
+					stateBatchAppendChan <- iter.Event
+					log.Warn("write additional event into channel, will ignore prev events")
 				}
 			}
 			_ = writeGasOracleSyncHeight(db, latestHeader.Number)
diff --git a/gas-oracle/oracle/overhead.go b/gas-oracle/oracle/overhead.go
index a2008d437..77b939aba 100644
--- a/gas-oracle/oracle/overhead.go
+++ b/gas-oracle/oracle/overhead.go
@@ -88,7 +88,11 @@ func wrapUpdateOverhead(l2Backend DeployContractBackend, cfg *Config) (func(*big
 		if err != nil {
 			return err
 		}
-
+		// skip update if overhead is not changed
+		if overhead == newOverheadLevel {
+			log.Info("skip update overhead", "overhead", overhead)
+			return nil
+		}
 		// Use the configured gas price if it is set,
 		// otherwise use gas estimation
 		if cfg.gasPrice != nil {