diff --git a/HISTORY.md b/HISTORY.md
index f277a39..d4874bf 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,5 +1,11 @@
 ## ✒ 历史版本的特性介绍 (Features in old versions)
 
+### v1.5.7-alpha
+
+> 此版本发布于 2023-12-22
+
+* 增加包级别的 Sync 和 Close 函数
+
 ### v1.5.6-alpha
 
 > 此版本发布于 2023-12-21
diff --git a/default.go b/default.go
index 305aa40..373c7f1 100644
--- a/default.go
+++ b/default.go
@@ -78,3 +78,13 @@ func Println(args ...interface{}) {
 	msg := fmt.Sprintln(args...)
 	Default().log(defaults.LevelPrint, msg)
 }
+
+// Sync syncs the default logger and returns an error if failed.
+func Sync() error {
+	return Default().Sync()
+}
+
+// Close closes the default logger and returns an error if failed.
+func Close() error {
+	return Default().Close()
+}
diff --git a/default_test.go b/default_test.go
index 686c1f4..86b3dac 100644
--- a/default_test.go
+++ b/default_test.go
@@ -88,3 +88,48 @@ func TestDefaultLogger(t *testing.T) {
 		t.Fatalf("got %s != want %s", got, want)
 	}
 }
+
+// go test -v -cover -count=1 -test.cpu=1 -run=^TestDefaultLoggerSync$
+func TestDefaultLoggerSync(t *testing.T) {
+	syncer := &testSyncer{
+		synced: false,
+	}
+
+	logger := &Logger{
+		syncer: syncer,
+	}
+
+	SetDefault(logger)
+	Sync()
+
+	if !syncer.synced {
+		t.Fatal("syncer.synced is wrong")
+	}
+}
+
+// go test -v -cover -count=1 -test.cpu=1 -run=^TestDefaultLoggerClose$
+func TestDefaultLoggerClose(t *testing.T) {
+	syncer := &testSyncer{
+		synced: false,
+	}
+
+	closer := &testCloser{
+		closed: false,
+	}
+
+	logger := &Logger{
+		syncer: syncer,
+		closer: closer,
+	}
+
+	SetDefault(logger)
+	Close()
+
+	if !syncer.synced {
+		t.Fatal("syncer.synced is wrong")
+	}
+
+	if !closer.closed {
+		t.Fatal("closer.closed is wrong")
+	}
+}
diff --git a/doc.go b/doc.go
index f5ba28f..3c2a68e 100644
--- a/doc.go
+++ b/doc.go
@@ -317,5 +317,5 @@ package logit // import "github.com/FishGoddess/logit"
 
 const (
 	// Version is the version string representation of logit.
-	Version = "v1.5.6-alpha"
+	Version = "v1.5.7-alpha"
 )
diff --git a/logger_test.go b/logger_test.go
index 5dbc346..31117f1 100644
--- a/logger_test.go
+++ b/logger_test.go
@@ -30,6 +30,24 @@ type testLoggerHandler struct {
 	opts slog.HandlerOptions
 }
 
+type testSyncer struct {
+	synced bool
+}
+
+func (ts *testSyncer) Sync() error {
+	ts.synced = true
+	return nil
+}
+
+type testCloser struct {
+	closed bool
+}
+
+func (tc *testCloser) Close() error {
+	tc.closed = true
+	return nil
+}
+
 // go test -v -cover -count=1 -test.cpu=1 -run=^TestNewLogger$
 func TestNewLogger(t *testing.T) {
 	handlerName := t.Name()
@@ -219,3 +237,46 @@ func TestLogger(t *testing.T) {
 		t.Fatalf("got %s != want %s", got, want)
 	}
 }
+
+// go test -v -cover -count=1 -test.cpu=1 -run=^TestLoggerSync$
+func TestLoggerSync(t *testing.T) {
+	syncer := &testSyncer{
+		synced: false,
+	}
+
+	logger := &Logger{
+		syncer: syncer,
+	}
+
+	logger.Sync()
+
+	if !syncer.synced {
+		t.Fatal("syncer.synced is wrong")
+	}
+}
+
+// go test -v -cover -count=1 -test.cpu=1 -run=^TestLoggerClose$
+func TestLoggerClose(t *testing.T) {
+	syncer := &testSyncer{
+		synced: false,
+	}
+
+	closer := &testCloser{
+		closed: false,
+	}
+
+	logger := &Logger{
+		syncer: syncer,
+		closer: closer,
+	}
+
+	logger.Close()
+
+	if !syncer.synced {
+		t.Fatal("syncer.synced is wrong")
+	}
+
+	if !closer.closed {
+		t.Fatal("closer.closed is wrong")
+	}
+}