diff --git a/README.md b/README.md
index 9d30370..98bbf9c 100644
--- a/README.md
+++ b/README.md
@@ -40,15 +40,15 @@ func main() {
 
 ```sh
 go test -count=1 -benchtime 5s -benchmem . -bench .
-0.9948495475
+0.9948804265
 goos: darwin
 goarch: amd64
 pkg: github.com/flyaways/timer
 cpu: Intel(R) Core(TM) i5-7360U CPU @ 2.30GHz
-BenchmarkFlyawaysTimer-4        239080164               25.83 ns/op            0 B/op          0 allocs/op
-BenchmarkTarsGoTimer-4          144200496               43.22 ns/op            0 B/op          0 allocs/op
-BenchmarkOfficalTimer-4          9556473               671.0 ns/op           206 B/op          3 allocs/op
-BenchmarkRussellLuoTimer-4      15525009               463.3 ns/op           167 B/op          2 allocs/op
+BenchmarkFlyawaysTimer-4        174450506               53.58 ns/op            0 B/op          0 allocs/op
+BenchmarkTarsGoTimer-4          79953462                74.30 ns/op            0 B/op          0 allocs/op
+BenchmarkOfficalTimer-4         12491235               519.6 ns/op           201 B/op          3 allocs/op
+BenchmarkRussellLuoTimer-4      13017769               514.1 ns/op           164 B/op          2 allocs/op
 PASS
-ok      github.com/flyaways/timer       44.648s
+ok      github.com/flyaways/timer       43.342s
 ```
diff --git a/benchmark_test.go b/benchmark_test.go
index c284d37..e48f3d5 100644
--- a/benchmark_test.go
+++ b/benchmark_test.go
@@ -11,23 +11,29 @@ import (
 //BenchmarkTimeWheel benchmarks timewheel.
 func BenchmarkFlyawaysTimer(b *testing.B) {
 	t := New(20, time.Millisecond*5)
-	for i := 0; i < b.N; i++ {
-		t.After(time.Millisecond * 100)
-	}
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			t.After(time.Millisecond * 100)
+		}
+	})
 }
 
 //BenchmarkTimeWheel benchmarks timewheel.
 func BenchmarkTarsGoTimer(b *testing.B) {
-	for i := 0; i < b.N; i++ {
-		rtimer.After(time.Millisecond * 100)
-	}
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			rtimer.After(time.Millisecond * 100)
+		}
+	})
 }
 
 //BenchmarkTimeBase benchmark origin timer.
 func BenchmarkOfficalTimer(b *testing.B) {
-	for i := 0; i < b.N; i++ {
-		time.After(time.Millisecond * 100)
-	}
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			time.After(time.Millisecond * 100)
+		}
+	})
 }
 
 //BenchmarkRussellLuoTimer benchmark timewheel.
@@ -36,7 +42,9 @@ func BenchmarkRussellLuoTimer(b *testing.B) {
 	tw.Start()
 	defer tw.Stop()
 
-	for i := 0; i < b.N; i++ {
-		tw.AfterFunc(time.Millisecond*100, func() {})
-	}
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			tw.AfterFunc(time.Millisecond*100, func() {})
+		}
+	})
 }