diff --git a/cmd/redis-shake/main.go b/cmd/redis-shake/main.go
index 3930ed83..12e22739 100644
--- a/cmd/redis-shake/main.go
+++ b/cmd/redis-shake/main.go
@@ -177,10 +177,17 @@ func main() {
 			theWriter = writer.NewRedisStandaloneWriter(ctx, opts)
 		}
 		if config.Opt.Advanced.EmptyDBBeforeSync {
-			// exec FLUSHALL command to flush db
-			entry := entry.NewEntry()
-			entry.Argv = []string{"FLUSHALL"}
-			theWriter.Write(entry)
+			if config.Opt.Advanced.EmptyDBByAsync {
+				log.Infof("execute FLUSHALL ASYNC to empty target db before sync")
+				if err := theWriter.FlushAllAsync(); err != nil {
+					log.Panicf("failed to flush target db: %v", err)
+				}
+			} else {
+				log.Infof("execute FLUSHALL to empty target db before sync")
+				flushEntry := entry.NewEntry()
+				flushEntry.Argv = []string{"FLUSHALL"}
+				theWriter.Write(flushEntry)
+			}
 		}
 	default:
 		log.Panicf("no writer config entry found")
diff --git a/internal/client/func.go b/internal/client/func.go
index 14488e71..586433b0 100644
--- a/internal/client/func.go
+++ b/internal/client/func.go
@@ -3,9 +3,13 @@ package client
 import (
 	"bytes"
 	"errors"
+	"fmt"
+	"strconv"
 	"strings"
+	"time"
 
 	"RedisShake/internal/client/proto"
+	"RedisShake/internal/config"
 	"RedisShake/internal/log"
 )
 
@@ -54,3 +58,38 @@ func (r *Redis) IsValkey() bool {
 	}
 	return isValkey
 }
+
+func (r *Redis) FlushAllAsync() error {
+	reply := r.DoWithStringReply("FLUSHALL", "ASYNC")
+	if reply != "OK" {
+		return fmt.Errorf("FLUSHALL ASYNC failed: %s", reply)
+	}
+
+	deadline := time.Now().Add(config.Opt.Advanced.LazyFreePendingObjectsMaxWait)
+	for time.Now().Before(deadline) {
+		info := r.DoWithStringReply("INFO", "memory")
+		pending := parseLazyFreePendingObjects(info)
+		if pending == 0 {
+			return nil
+		}
+		time.Sleep(config.Opt.Advanced.LazyFreePendingObjectsCheckInterval)
+	}
+	return fmt.Errorf("timeout waiting for lazyfree_pending_objects to be 0")
+}
+
+func parseLazyFreePendingObjects(info string) int {
+	for _, line := range strings.Split(info, "\n") {
+		line = strings.TrimSpace(line)
+		if strings.HasPrefix(line, "lazyfree_pending_objects:") {
+			parts := strings.Split(line, ":")
+			if len(parts) >= 2 {
+				val, err := strconv.Atoi(strings.TrimSpace(parts[1]))
+				if err != nil {
+					return -1
+				}
+				return val
+			}
+		}
+	}
+	return -1
+}
diff --git a/internal/client/func_test.go b/internal/client/func_test.go
index e11b2245..b89d362a 100644
--- a/internal/client/func_test.go
+++ b/internal/client/func_test.go
@@ -126,3 +126,57 @@ redis_mode:standalone
 		})
 	}
 }
+
+func TestParseLazyFreePendingObjects(t *testing.T) {
+	tests := []struct {
+		name string
+		info string
+		want int
+	}{
+		{
+			name: "lazyfree_pending_objects is 0",
+			info: `# Stats
+lazyfree_pending_objects:0
+used_cpu_sys:0.5
+`,
+			want: 0,
+		},
+		{
+			name: "lazyfree_pending_objects is 5",
+			info: `# Stats
+lazyfree_pending_objects:5
+used_cpu_sys:0.5
+`,
+			want: 5,
+		},
+		{
+			name: "no lazyfree_pending_objects field",
+			info: `# Stats
+used_cpu_sys:0.5
+`,
+			want: -1,
+		},
+		{
+			name: "empty info",
+			info: ``,
+			want: -1,
+		},
+		{
+			name: "lazyfree_pending_objects with spaces",
+			info: `# Stats
+lazyfree_pending_objects:   10
+used_cpu_sys:0.5
+`,
+			want: 10,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := parseLazyFreePendingObjects(tt.info)
+			if got != tt.want {
+				t.Errorf("parseLazyFreePendingObjects() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
diff --git a/internal/config/config.go b/internal/config/config.go
index 68cb13d3..0525c54e 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -7,6 +7,7 @@ import (
 	"os"
 	"regexp"
 	"strings"
+	"time"
 
 	"github.com/mcuadros/go-defaults"
 	"github.com/rs/zerolog"
@@ -75,6 +76,13 @@ type AdvancedOptions struct {
 	AwsPSync string `mapstructure:"aws_psync" default:""` // 10.0.0.1:6379@nmfu2sl5osync,10.0.0.1:6379@xhma21xfkssync
 
 	EmptyDBBeforeSync bool `mapstructure:"empty_db_before_sync" default:"false"`
+
+	// flush options
+	// When true, uses FLUSHALL ASYNC and waits for lazyfree_pending_objects to be 0.
+	// When false, skips flush operation.
+	EmptyDBByAsync                      bool          `mapstructure:"empty_db_by_async" default:"false"`
+	LazyFreePendingObjectsMaxWait       time.Duration `mapstructure:"lazy_free_pending_objects_max_wait" default:"60s"`
+	LazyFreePendingObjectsCheckInterval time.Duration `mapstructure:"lazy_free_pending_objects_check_interval" default:"100ms"`
 }
 
 type ModuleOptions struct {
diff --git a/internal/writer/file_writer.go b/internal/writer/file_writer.go
index ef4dacbc..3a578753 100644
--- a/internal/writer/file_writer.go
+++ b/internal/writer/file_writer.go
@@ -127,3 +127,7 @@ func (w *fileWriter) writeEntry(writer *bufio.Writer, e *entry.Entry) {
 		writer.WriteString("\n")
 	}
 }
+
+func (w *fileWriter) FlushAllAsync() error {
+	return nil
+}
diff --git a/internal/writer/interface.go b/internal/writer/interface.go
index 21329d29..bdbdad3a 100644
--- a/internal/writer/interface.go
+++ b/internal/writer/interface.go
@@ -11,4 +11,5 @@ type Writer interface {
 	Write(entry *entry.Entry)
 	StartWrite(ctx context.Context) (ch chan *entry.Entry)
 	Close()
+	FlushAllAsync() error
 }
diff --git a/internal/writer/redis_cluster_writer.go b/internal/writer/redis_cluster_writer.go
index 40f193f5..44354601 100644
--- a/internal/writer/redis_cluster_writer.go
+++ b/internal/writer/redis_cluster_writer.go
@@ -121,3 +121,12 @@ func (r *RedisClusterWriter) StatusConsistent() bool {
 	}
 	return true
 }
+
+func (r *RedisClusterWriter) FlushAllAsync() error {
+	for _, writer := range r.writers {
+		if err := writer.FlushAllAsync(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/internal/writer/redis_standalone_writer.go b/internal/writer/redis_standalone_writer.go
index b8070947..db603444 100644
--- a/internal/writer/redis_standalone_writer.go
+++ b/internal/writer/redis_standalone_writer.go
@@ -181,3 +181,7 @@ func (w *redisStandaloneWriter) StatusString() string {
 func (w *redisStandaloneWriter) StatusConsistent() bool {
 	return atomic.LoadInt64(&w.stat.UnansweredBytes) == 0 && atomic.LoadInt64(&w.stat.UnansweredEntries) == 0
 }
+
+func (w *redisStandaloneWriter) FlushAllAsync() error {
+	return w.client.FlushAllAsync()
+}
diff --git a/shake.toml b/shake.toml
index f0bf612f..29f01326 100644
--- a/shake.toml
+++ b/shake.toml
@@ -166,6 +166,17 @@ aws_psync = "" # example: aws_psync = "10.0.0.1:6379@nmfu2sl5osync,10.0.0.1:6379
 #   repl-diskless-load on-empty-db
 empty_db_before_sync = false
 
+# FLUSHALL ASYNC options
+# When true, uses FLUSHALL ASYNC and waits for lazyfree_pending_objects to be 0.
+# When false, uses synchronous FLUSHALL.
+empty_db_by_async = false
+# The maximum time to wait for lazyfree_pending_objects to be 0
+# Default: 60s
+lazy_free_pending_objects_max_wait = "60s"
+# The interval to check lazyfree_pending_objects status
+# Default: 100ms
+lazy_free_pending_objects_check_interval = "100ms"
+
 [module]
 # The data format for BF.LOADCHUNK is not compatible in different versions. v2.6.3 <=> 20603
 target_mbbloom_version = 20603