diff --git a/cmd/pd-server/main.go b/cmd/pd-server/main.go
index 0bf28ccfdea..bd75309ed8a 100644
--- a/cmd/pd-server/main.go
+++ b/cmd/pd-server/main.go
@@ -102,7 +102,7 @@ func NewTSOServiceCommand() *cobra.Command {
 	cmd.Flags().StringP("cacert", "", "", "path of file that contains list of trusted TLS CAs")
 	cmd.Flags().StringP("cert", "", "", "path of file that contains X509 certificate in PEM format")
 	cmd.Flags().StringP("key", "", "", "path of file that contains X509 key in PEM format")
-	cmd.Flags().StringP("log-level", "L", "info", "log level: debug, info, warn, error, fatal (default 'info')")
+	cmd.Flags().StringP("log-level", "L", "", "log level: debug, info, warn, error, fatal (default 'info')")
 	cmd.Flags().StringP("log-file", "", "", "log file path")
 	return cmd
 }
@@ -122,7 +122,7 @@ func NewSchedulingServiceCommand() *cobra.Command {
 	cmd.Flags().StringP("cacert", "", "", "path of file that contains list of trusted TLS CAs")
 	cmd.Flags().StringP("cert", "", "", "path of file that contains X509 certificate in PEM format")
 	cmd.Flags().StringP("key", "", "", "path of file that contains X509 key in PEM format")
-	cmd.Flags().StringP("log-level", "L", "info", "log level: debug, info, warn, error, fatal (default 'info')")
+	cmd.Flags().StringP("log-level", "L", "", "log level: debug, info, warn, error, fatal (default 'info')")
 	cmd.Flags().StringP("log-file", "", "", "log file path")
 	return cmd
 }
@@ -142,7 +142,7 @@ func NewResourceManagerServiceCommand() *cobra.Command {
 	cmd.Flags().StringP("cacert", "", "", "path of file that contains list of trusted TLS CAs")
 	cmd.Flags().StringP("cert", "", "", "path of file that contains X509 certificate in PEM format")
 	cmd.Flags().StringP("key", "", "", "path of file that contains X509 key in PEM format")
-	cmd.Flags().StringP("log-level", "L", "info", "log level: debug, info, warn, error, fatal (default 'info')")
+	cmd.Flags().StringP("log-level", "L", "", "log level: debug, info, warn, error, fatal (default 'info')")
 	cmd.Flags().StringP("log-file", "", "", "log file path")
 	return cmd
 }
@@ -171,7 +171,7 @@ func addFlags(cmd *cobra.Command) {
 	cmd.Flags().StringP("initial-cluster", "", "", "initial cluster configuration for bootstrapping, e,g. pd=http://127.0.0.1:2380")
 	cmd.Flags().StringP("join", "", "", "join to an existing cluster (usage: cluster's '${advertise-client-urls}'")
 	cmd.Flags().StringP("metrics-addr", "", "", "prometheus pushgateway address, leaves it empty will disable prometheus push")
-	cmd.Flags().StringP("log-level", "L", "info", "log level: debug, info, warn, error, fatal (default 'info')")
+	cmd.Flags().StringP("log-level", "L", "", "log level: debug, info, warn, error, fatal (default 'info')")
 	cmd.Flags().StringP("log-file", "", "", "log file path")
 	cmd.Flags().StringP("cacert", "", "", "path of file that contains list of trusted TLS CAs")
 	cmd.Flags().StringP("cert", "", "", "path of file that contains X509 certificate in PEM format")
diff --git a/pkg/mcs/resourcemanager/server/config.go b/pkg/mcs/resourcemanager/server/config.go
index 508f37fe069..72547a4cc4e 100644
--- a/pkg/mcs/resourcemanager/server/config.go
+++ b/pkg/mcs/resourcemanager/server/config.go
@@ -236,10 +236,6 @@ func (c *Config) Adjust(meta *toml.MetaData, reloading bool) error {
 	c.adjustLog(configMetaData.Child("log"))
 	c.Security.Encryption.Adjust()
 
-	if len(c.Log.Format) == 0 {
-		c.Log.Format = utils.DefaultLogFormat
-	}
-
 	c.Controller.Adjust(configMetaData.Child("controller"))
 	configutil.AdjustInt64(&c.LeaderLease, utils.DefaultLeaderLease)
 
@@ -250,6 +246,8 @@ func (c *Config) adjustLog(meta *configutil.ConfigMetaData) {
 	if !meta.IsDefined("disable-error-verbose") {
 		c.Log.DisableErrorVerbose = utils.DefaultDisableErrorVerbose
 	}
+	configutil.AdjustString(&c.Log.Format, utils.DefaultLogFormat)
+	configutil.AdjustString(&c.Log.Level, utils.DefaultLogLevel)
 }
 
 // GetName returns the Name
diff --git a/pkg/mcs/scheduling/server/config/config.go b/pkg/mcs/scheduling/server/config/config.go
index 3e347afc12e..b342724e74c 100644
--- a/pkg/mcs/scheduling/server/config/config.go
+++ b/pkg/mcs/scheduling/server/config/config.go
@@ -148,10 +148,6 @@ func (c *Config) adjust(meta *toml.MetaData) error {
 	c.adjustLog(configMetaData.Child("log"))
 	c.Security.Encryption.Adjust()
 
-	if len(c.Log.Format) == 0 {
-		c.Log.Format = utils.DefaultLogFormat
-	}
-
 	configutil.AdjustInt64(&c.LeaderLease, utils.DefaultLeaderLease)
 
 	if err := c.Schedule.Adjust(configMetaData.Child("schedule"), false); err != nil {
@@ -164,6 +160,8 @@ func (c *Config) adjustLog(meta *configutil.ConfigMetaData) {
 	if !meta.IsDefined("disable-error-verbose") {
 		c.Log.DisableErrorVerbose = utils.DefaultDisableErrorVerbose
 	}
+	configutil.AdjustString(&c.Log.Format, utils.DefaultLogFormat)
+	configutil.AdjustString(&c.Log.Level, utils.DefaultLogLevel)
 }
 
 // GetName returns the Name
diff --git a/pkg/mcs/tso/server/config.go b/pkg/mcs/tso/server/config.go
index eedf3a2f1b1..165ff904dc4 100644
--- a/pkg/mcs/tso/server/config.go
+++ b/pkg/mcs/tso/server/config.go
@@ -226,10 +226,6 @@ func (c *Config) Adjust(meta *toml.MetaData, reloading bool) error {
 	c.adjustLog(configMetaData.Child("log"))
 	c.Security.Encryption.Adjust()
 
-	if len(c.Log.Format) == 0 {
-		c.Log.Format = utils.DefaultLogFormat
-	}
-
 	return nil
 }
 
@@ -237,6 +233,8 @@ func (c *Config) adjustLog(meta *configutil.ConfigMetaData) {
 	if !meta.IsDefined("disable-error-verbose") {
 		c.Log.DisableErrorVerbose = utils.DefaultDisableErrorVerbose
 	}
+	configutil.AdjustString(&c.Log.Format, utils.DefaultLogFormat)
+	configutil.AdjustString(&c.Log.Level, utils.DefaultLogLevel)
 }
 
 // Validate is used to validate if some configurations are right.
diff --git a/pkg/mcs/utils/constant.go b/pkg/mcs/utils/constant.go
index 21b57a3c5c5..c6c882f5179 100644
--- a/pkg/mcs/utils/constant.go
+++ b/pkg/mcs/utils/constant.go
@@ -32,6 +32,8 @@ const (
 	DefaultHTTPGracefulShutdownTimeout = 5 * time.Second
 	// DefaultLogFormat is the default log format
 	DefaultLogFormat = "text"
+	// DefaultLogLevel is the default log level
+	DefaultLogLevel = "info"
 	// DefaultDisableErrorVerbose is the default value of DisableErrorVerbose
 	DefaultDisableErrorVerbose = true
 	// DefaultLeaderLease is the default value of LeaderLease
diff --git a/server/config/config.go b/server/config/config.go
index 93aa3bb87d3..95d5dcb3257 100644
--- a/server/config/config.go
+++ b/server/config/config.go
@@ -234,6 +234,7 @@ const (
 	minTSOUpdatePhysicalInterval     = 1 * time.Millisecond
 
 	defaultLogFormat = "text"
+	defaultLogLevel  = "info"
 
 	defaultServerMemoryLimit          = 0
 	minServerMemoryLimit              = 0
@@ -468,10 +469,6 @@ func (c *Config) Adjust(meta *toml.MetaData, reloading bool) error {
 
 	c.Security.Encryption.Adjust()
 
-	if len(c.Log.Format) == 0 {
-		c.Log.Format = defaultLogFormat
-	}
-
 	c.Controller.Adjust(configMetaData.Child("controller"))
 
 	return nil
@@ -481,6 +478,8 @@ func (c *Config) adjustLog(meta *configutil.ConfigMetaData) {
 	if !meta.IsDefined("disable-error-verbose") {
 		c.Log.DisableErrorVerbose = defaultDisableErrorVerbose
 	}
+	configutil.AdjustString(&c.Log.Format, defaultLogFormat)
+	configutil.AdjustString(&c.Log.Level, defaultLogLevel)
 }
 
 // Clone returns a cloned configuration.
diff --git a/server/config/config_test.go b/server/config/config_test.go
index 69cfafd8d36..d7abfe0746a 100644
--- a/server/config/config_test.go
+++ b/server/config/config_test.go
@@ -246,6 +246,22 @@ tso-update-physical-interval = "15s"
 	re.NoError(err)
 
 	re.Equal(maxTSOUpdatePhysicalInterval, cfg.TSOUpdatePhysicalInterval.Duration)
+
+	cfgData = `
+[log]
+level = "debug"
+`
+	flagSet = pflag.NewFlagSet("testlog", pflag.ContinueOnError)
+	flagSet.StringP("log-level", "L", "info", "log level: debug, info, warn, error, fatal (default 'info')")
+	flagSet.Parse(nil)
+	cfg = NewConfig()
+	err = cfg.Parse(flagSet)
+	re.NoError(err)
+	meta, err = toml.Decode(cfgData, &cfg)
+	re.NoError(err)
+	err = cfg.Adjust(&meta, false)
+	re.NoError(err)
+	re.Equal("debug", cfg.Log.Level)
 }
 
 func TestMigrateFlags(t *testing.T) {