diff --git a/pkg/schedule/config/config.go b/pkg/schedule/config/config.go
index f87b702e0b2..4d5db6a26be 100644
--- a/pkg/schedule/config/config.go
+++ b/pkg/schedule/config/config.go
@@ -30,12 +30,12 @@ const (
 	DefaultMaxReplicas            = 3
 	defaultMaxSnapshotCount       = 64
 	defaultMaxPendingPeerCount    = 64
-	defaultMaxMergeRegionSize     = 20
+	defaultMaxMergeRegionSize     = 0
 	defaultLeaderScheduleLimit    = 4
 	defaultRegionScheduleLimit    = 2048
 	defaultWitnessScheduleLimit   = 4
 	defaultReplicaScheduleLimit   = 64
-	defaultMergeScheduleLimit     = 8
+	defaultMergeScheduleLimit     = 0
 	defaultHotRegionScheduleLimit = 4
 	defaultTolerantSizeRatio      = 0
 	defaultLowSpaceRatio          = 0.8
diff --git a/server/config/persist_options.go b/server/config/persist_options.go
index ccb893eef03..1ea0b79424f 100644
--- a/server/config/persist_options.go
+++ b/server/config/persist_options.go
@@ -764,11 +764,9 @@ type persistedConfig struct {
 
 // Persist saves the configuration to the storage.
 func (o *PersistOptions) Persist(storage endpoint.ConfigStorage) error {
-	schedulerCfg := o.GetScheduleConfig()
-	schedulerCfg.MaxMergeRegionSize = 0
 	cfg := &persistedConfig{
 		Config: &Config{
-			Schedule:        *schedulerCfg,
+			Schedule:        *o.GetScheduleConfig(),
 			Replication:     *o.GetReplicationConfig(),
 			PDServerCfg:     *o.GetPDServerConfig(),
 			ReplicationMode: *o.GetReplicationModeConfig(),