diff --git a/iterator.go b/iterator.go
index 2e1e564..435adeb 100644
--- a/iterator.go
+++ b/iterator.go
@@ -63,28 +63,38 @@ func NewIter(ipStr string) (it *Iter, startIp net.IP, err error) {
 	} else if strings.Contains(ipStr, ":") {
 		it.isIpv6 = true
 		// 填充缩写
-		if strings.Count(ipStr, "::") == 1 {
-			// :: 扩展
-			buf := ":0000"
-			for i := strings.Count(ipStr, ":"); i < 7; i++ {
-				buf += ":0000"
-			}
-			ipStr = strings.Replace(ipStr, "::", buf+":", 1)
 
-			// 补零
-			ipv6C := strings.Split(ipStr, ":")
-			for i, v := range ipv6C {
-				ipv6D := strings.Split(v, "-")
-				for i2, v2 := range ipv6D {
-					for len(v2) < 4 {
-						v2 = "0" + v2
-					}
-					ipv6D[i2] = v2
+		// :: 扩展
+		var fill = func(ipStr string) string {
+			buf := strings.Builder{}
+			for i := strings.Count(ipStr, ":"); i < 8; i++ {
+				buf.WriteString(":0000")
+			}
+			ipStr = strings.Replace(ipStr, "::", buf.String()+":", 1)
+			buf.Reset()
+			return ipStr
+		}
+		if strings.Count(ipStr, "::") == 1 {
+			ipStr = fill(ipStr)
+		} else if strings.Count(ipStr, "::") == 2 && strings.Count(ipStr, "-") == 1 {
+			iL := strings.Split(ipStr, "-")
+			iL[0] = fill(iL[0])
+			iL[1] = fill(iL[1])
+			ipStr = strings.Join(iL, "-")
+		}
+		// 补零
+		ipv6C := strings.Split(ipStr, ":")
+		for i, v := range ipv6C {
+			ipv6D := strings.Split(v, "-")
+			for i2, v2 := range ipv6D {
+				for len(v2) < 4 {
+					v2 = "0" + v2
 				}
-				ipv6C[i] = strings.Join(ipv6D, "-")
+				ipv6D[i2] = v2
 			}
-			ipStr = strings.Join(ipv6C, ":")
+			ipv6C[i] = strings.Join(ipv6D, "-")
 		}
+		ipStr = strings.Join(ipv6C, ":")
 	}
 	it.ipStr = ipStr
 	if !it.isIpv4 && !it.isIpv6 {
diff --git a/iterator_test.go b/iterator_test.go
index 57eb080..a579c38 100644
--- a/iterator_test.go
+++ b/iterator_test.go
@@ -1,14 +1,31 @@
 package iprange
 
 import (
+	"fmt"
 	"net"
 	"testing"
 )
 
 func TestName(t *testing.T) {
-	for _, v := range []string{"1.1.1.1", "1.1.1.2/30", "1.1.1.0-255", "1.1-2.0-1.4", "1.1.1.1-1.1.2.1", "2001::59:63", "2001::59:63/126", "2001::59:63-f2", "2001::59-60:63-f2", "2001::59:63-2001::59:f2"} {
-		t.Logf("Test %s", v)
-		it, startIp, err := NewIter(v)
+	testCases := []struct {
+		input string
+		want  string
+	}{
+		{input: "1.1.1.1", want: "1.1.1.1"},
+		{input: "1.1.1.2/30", want: "1.1.1.3"},
+		{input: "1.1.1.0-255", want: "1.1.1.200"},
+		{input: "1.1-2.0-1.4", want: "1.2.0.4"},
+		{input: "1.1.1.1-1.1.2.1", want: "1.1.2.0"},
+		{input: "2001::59:63", want: "2001::59:63"},
+		{input: "2001::59:63/126", want: "2001::59:62"},
+		{input: "2001::59:63-f2", want: "2001::59:f0"},
+		{input: "2001::59-60:63-f2", want: "2001::60:f0"},
+		{input: "2001::59:63-2001::59:f2", want: "2001::59:f0"},
+	}
+
+	for _, v := range testCases {
+		t.Logf("Test %s", v.input)
+		it, startIp, err := NewIter(v.input)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -30,17 +47,18 @@ func TestName(t *testing.T) {
 
 		// 迭代
 		it.GetIpByIndex(0) // rest index
-		for itn := startIp; it.HasNext(); itn = it.Next() {
+		i := 0
+		for itn := startIp; it.HasNext() && i <= 3; itn = it.Next() {
 			t.Log(itn)
+			i++
 		}
 
 		// 包含判断
-		t.Log("Contains 1.1.1.0?", it.Contains(net.ParseIP("1.1.1.0")))
-		t.Log("Contains 1.1.1.1?", it.Contains(net.ParseIP("1.1.1.1")))
-		t.Log("Contains 1.1.1.3?", it.Contains(net.ParseIP("1.1.1.3")))
-		t.Log("Contains 2001::59:63?", it.Contains(net.ParseIP("2001::59:63")))
-		t.Log("Contains 2001::59:f2?", it.Contains(net.ParseIP("2001::59:f2")))
-		t.Log("Contains 2001::59:f3?", it.Contains(net.ParseIP("2001::59:f3")))
+		if !it.Contains(net.ParseIP(v.want)) {
+			t.Error(fmt.Sprintf("[ERR] %s Contains %s?", v.input, v.want), it.Contains(net.ParseIP(v.want)))
+		} else {
+			t.Log(fmt.Sprintf("%s Contains %s?", v.input, v.want), it.Contains(net.ParseIP(v.want)))
+		}
 	}
 
 	// 简单的获取IP序列