diff --git a/dogecoin/dogedust.go b/dogecoin/dogedust.go
index b0dc27a..e6b8746 100644
--- a/dogecoin/dogedust.go
+++ b/dogecoin/dogedust.go
@@ -1,6 +1,10 @@
 package dogecoin
 
-import "github.com/yyle88/gobtcsign/internal/dusts"
+import (
+	"github.com/btcsuite/btcd/btcutil"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/yyle88/gobtcsign/internal/dusts"
+)
 
 const (
 	// MinDustOutput 硬性灰尘数量，详见 https://github.com/dogecoin/dogecoin/blob/master/doc/fee-recommendation.md
@@ -15,9 +19,21 @@ const (
 
 type DustFee = dusts.DustFee
 
+// NewDogeDustFee 配置狗狗币的dust费用
+// 具体参考链接在
+// https://github.com/dogecoin/dogecoin/blob/b4a5d2bef20f5cca54d9c14ca118dec259e47bb4/doc/fee-recommendation.md
+// DOGECOIN 简单规定了软灰尘和硬灰尘，假如是硬灰尘会被拒绝，假如是软灰尘会收取额外的费用
 func NewDogeDustFee() DustFee {
 	res := dusts.NewDustFee()
 	res.SoftDustSize = SoftDustLimit
 	res.ExtraDustFee = ExtraDustsFee
 	return res
 }
+
+type DustLimit = dusts.DustLimit
+
+func NewDogeDustLimit() *DustLimit {
+	return dusts.NewDustLimit(func(output *wire.TxOut, relayFeePerKb btcutil.Amount) bool {
+		return output.Value < MinDustOutput //在dogecoin中的灰尘规定比较简单，它不依赖于费率，而是直接和常量比较，逻辑简单
+	})
+}
diff --git a/internal/dusts/txout_dust.go b/internal/dusts/txout_dust.go
new file mode 100644
index 0000000..57da45e
--- /dev/null
+++ b/internal/dusts/txout_dust.go
@@ -0,0 +1,18 @@
+package dusts
+
+import (
+	"github.com/btcsuite/btcd/btcutil"
+	"github.com/btcsuite/btcd/wire"
+)
+
+type DustLimit struct {
+	check func(output *wire.TxOut, relayFeePerKb btcutil.Amount) bool
+}
+
+func NewDustLimit(check func(output *wire.TxOut, relayFeePerKb btcutil.Amount) bool) *DustLimit {
+	return &DustLimit{check: check}
+}
+
+func (D *DustLimit) IsDustOutput(output *wire.TxOut, relayFeePerKb btcutil.Amount) bool {
+	return D.check(output, relayFeePerKb)
+}
diff --git a/txdust.go b/txdust.go
new file mode 100644
index 0000000..fe7e732
--- /dev/null
+++ b/txdust.go
@@ -0,0 +1,18 @@
+package gobtcsign
+
+import (
+	"github.com/btcsuite/btcwallet/wallet/txrules"
+	"github.com/yyle88/gobtcsign/internal/dusts"
+)
+
+type DustFee = dusts.DustFee
+
+func NewDustFee() DustFee {
+	return dusts.NewDustFee() //比特币没有软灰尘收费，这里配置个空的（因为doge里有，这里为了逻辑相通，而给个空的）
+}
+
+type DustLimit = dusts.DustLimit
+
+func NewDustLimit() *DustLimit {
+	return dusts.NewDustLimit(txrules.IsDustOutput)
+}
diff --git a/txdust_test.go b/txdust_test.go
new file mode 100644
index 0000000..4a565b5
--- /dev/null
+++ b/txdust_test.go
@@ -0,0 +1,112 @@
+package gobtcsign
+
+import (
+	"testing"
+
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/stretchr/testify/require"
+	"github.com/yyle88/gobtcsign/dogecoin"
+)
+
+func TestIsDustOutput_BTC(t *testing.T) {
+	netParams := chaincfg.MainNetParams
+
+	dustLimit := NewDustLimit()
+
+	const address = "1MAgFFbMpgx6hTPvK3HY348Bbnwk6RFHm5"
+	const feeRate = 1234000 //假设手续费是这个数
+
+	amount := int64(100000)
+	for {
+		output := wire.NewTxOut(amount, MustGetPkScript(MustNewAddress(address, &netParams)))
+		if !dustLimit.IsDustOutput(output, feeRate) {
+			break
+		}
+		amount++
+	}
+	t.Log("amount:", amount, "IS NOT DUST IN BTC")
+	t.Log("amount:", amount-1, "IS DUST IN BTC")
+}
+
+func TestIsDustOutput_BTC_2(t *testing.T) {
+	netParams := chaincfg.MainNetParams
+
+	dustLimit := NewDustLimit()
+
+	const address = "1MAgFFbMpgx6hTPvK3HY348Bbnwk6RFHm5"
+	const feeRate = 1000 //假设手续费是这个数
+
+	amount := int64(1)
+	for {
+		output := wire.NewTxOut(amount, MustGetPkScript(MustNewAddress(address, &netParams)))
+		if !dustLimit.IsDustOutput(output, feeRate) {
+			break
+		}
+		amount++
+	}
+	require.Equal(t, int64(546), amount) //这就是有的教程和代码里写 546 的依据
+	// 546 是比特币网络中一个常见的 Dust Threshold（灰尘阈值），其来源与比特币的交易手续费和 UTXO（未花费交易输出，Unspent Transaction Output）管理策略相关。
+	// 具体来说，546 是在默认设置下，比特币 Core 客户端用于计算 Dust Output（灰尘输出）的默认值。
+	// 比特币网络中最早的版本采用的是类似值，后来进行了微调，但很多第三方实现（例如钱包）仍然保留 546 的惯例。
+	t.Log("amount:", amount, "IS NOT DUST IN BTC")
+	t.Log("amount:", amount-1, "IS DUST IN BTC")
+}
+
+func TestIsDustOutput_BTC_3(t *testing.T) {
+	netParams := chaincfg.TestNet3Params
+
+	dustLimit := NewDustLimit()
+
+	const address = "tb1qy2f7svy0hp57wz3p6hvu0vf5fys750932ct3q5"
+	const feeRate = 1000 //假设手续费是这个数
+
+	amount := int64(1)
+	for {
+		output := wire.NewTxOut(amount, MustGetPkScript(MustNewAddress(address, &netParams)))
+		if !dustLimit.IsDustOutput(output, feeRate) {
+			break
+		}
+		amount++
+	}
+	require.Equal(t, int64(294), amount) //当地址类型为 P2WPKH 时由于其 输入大小比 P2PKH 小得多，因此灰尘阈值也更小些
+	// 因此有的代码里会这样写
+	// DustLimit returns the output dust limit (lowest possible satoshis in a UTXO) for the address type.
+	// func (a Address) DustLimit() int64 {
+	//		switch a.encodedType {
+	//		case AddressP2TR:
+	//			return 330
+	//		case AddressP2WPKH:
+	//			return 294
+	//		default:
+	//			return 546
+	//		}
+	// }
+	// 但实际上大家还都是使用 out >= 546 作为限制
+	t.Log("amount:", amount, "IS NOT DUST IN BTC")
+	t.Log("amount:", amount-1, "IS DUST IN BTC")
+}
+
+func TestIsDustOutput_DOGE(t *testing.T) {
+	netParams := dogecoin.TestNetParams
+
+	dustLimit := dogecoin.NewDogeDustLimit()
+	{
+		const amount = 500
+		const address = "nr2XmwqixAdXwkgVyshx3HPFRMfXugM8Zi"
+		const feeRate = 0 //这个不重要
+
+		output := wire.NewTxOut(amount, MustGetPkScript(MustNewAddress(address, &netParams)))
+		require.True(t, dustLimit.IsDustOutput(output, feeRate))
+		t.Log("amount:", amount, "IS DUST IN DOGE")
+	}
+	{
+		const amount = 100000
+		const address = "nqedQEDCgwrXqLd2JrrpCfD9Tcz384rdHA"
+		const feeRate = 0 //这个不重要
+
+		output := wire.NewTxOut(amount, MustGetPkScript(MustNewAddress(address, &netParams)))
+		require.False(t, dustLimit.IsDustOutput(output, feeRate))
+		t.Log("amount:", amount, "IS NOT DUST IN DOGE")
+	}
+}
diff --git a/txfee.go b/txfee.go
index 754e02c..e040291 100644
--- a/txfee.go
+++ b/txfee.go
@@ -8,19 +8,15 @@ import (
 	"github.com/btcsuite/btcwallet/wallet/txrules"
 	"github.com/btcsuite/btcwallet/wallet/txsizes"
 	"github.com/pkg/errors"
-	"github.com/yyle88/gobtcsign/internal/dusts"
 )
 
-type DustFee = dusts.DustFee
-
-func NewDustFee() DustFee {
-	return dusts.NewDustFee() //比特币没有软灰尘收费，这里配置个空的（因为doge里有，这里为了逻辑相通，而给个空的）
-}
-
 // EstimateTxFee 通过未签名且未找零的交易，预估出需要的费用
 // 代码基本是仿照这里的 github.com/btcsuite/btcwallet/wallet/txauthor@v1.3.4/author.go 里面 NewUnsignedTransaction 的逻辑
+// 具体参考链接在
+// https://github.com/btcsuite/btcwallet/blob/b4ff60753aaa3cf885fb09586755f67d41954942/wallet/txauthor/author.go#L132
 // 由于是计算手续费的，因为这个交易里不应该包含找零的 output 信息，否则结果是无意义的
 func EstimateTxFee(param *CustomParam, netParams *chaincfg.Params, change *ChangeTo, feeRatePerKb btcutil.Amount, dustFee DustFee) (btcutil.Amount, error) {
+	//通过未签名的交易预估出签名后的交易大小，这里预估值会比线上的值略微大些，误差在个位数（具体看vin和out的个数）
 	maxSignedSize, err := EstimateTxSize(param, netParams, change)
 	if err != nil {
 		return 0, errors.WithMessage(err, "wrong estimate-tx-size")
@@ -55,6 +51,8 @@ func EstimateTxSize(param *CustomParam, netParams *chaincfg.Params, change *Chan
 // EstimateSize 计算交易的预估大小（在最坏情况下的预估大小）
 // 这个函数还是抄的 github.com/btcsuite/btcwallet/wallet/txauthor@v1.3.4/author.go 里面 NewUnsignedTransaction 的逻辑
 // 详细细节见 https://github.com/btcsuite/btcwallet/blob/master/wallet/txauthor/author.go 这里的逻辑
+// 具体参考链接在
+// https://github.com/btcsuite/btcwallet/blob/b4ff60753aaa3cf885fb09586755f67d41954942/wallet/txauthor/author.go#L93
 // 是否填写找零信息，得依据 outputs 里面是否已经包含找零信息
 func EstimateSize(scripts [][]byte, outputs []*wire.TxOut, change *ChangeTo) (int, error) {
 	changeScriptSize, err := change.GetChangeScriptSize()
@@ -81,21 +79,25 @@ func EstimateSize(scripts [][]byte, outputs []*wire.TxOut, change *ChangeTo) (in
 	}
 
 	// 仿照这个函数 txauthor.NewUnsignedTransaction() 里的预估逻辑
+	// 通过未签名的交易信息，估算出要发送上链的交易体的大小，其中每个vin/out的误差至多是个位数的，累计起来误差不大，能够用来预估交易费用
 	maxSignedSize := txsizes.EstimateVirtualSize(
 		p2pkh, p2tr, p2wpkh, nested, outputs, changeScriptSize,
 	)
 	return maxSignedSize, nil
 }
 
+// ChangeTo 找零信息，这里为了方便使用，就设置两个属性二选一即可，优先使用公钥哈希，其次使用钱包地址
 type ChangeTo struct {
 	PkScript []byte          //允许为空，当两者皆为空时表示没有找零输出
 	AddressX btcutil.Address //允许为空，当两者皆为空时表示没有找零输出
 }
 
+// NewNoChange 当不需要找零时两个成员都是空
 func NewNoChange() *ChangeTo {
 	return &ChangeTo{}
 }
 
+// GetChangeScriptSize 计算出找零输出的size
 func (T *ChangeTo) GetChangeScriptSize() (int, error) {
 	if T.PkScript != nil { //优先使用找零脚本进行计算
 		return CalculateChangePkScriptSize(T.PkScript)
@@ -106,6 +108,7 @@ func (T *ChangeTo) GetChangeScriptSize() (int, error) {
 	return 0, nil //说明不需要找零输出，就返回0
 }
 
+// CalculateChangeAddressSize 根据钱包地址计算出找零输出的size
 func CalculateChangeAddressSize(address btcutil.Address) (int, error) {
 	pkScript, err := txscript.PayToAddrScript(address)
 	if err != nil {
@@ -114,6 +117,10 @@ func CalculateChangeAddressSize(address btcutil.Address) (int, error) {
 	return CalculateChangePkScriptSize(pkScript)
 }
 
+// CalculateChangePkScriptSize 根据公钥哈希计算出找零输出的size
+// 具体参考链接在
+// https://github.com/btcsuite/btcwallet/blob/b4ff60753aaa3cf885fb09586755f67d41954942/wallet/createtx.go#L457
+// 当然这里代码略有差异，但含义是相同的
 func CalculateChangePkScriptSize(pkScript []byte) (int, error) {
 	var size int
 	switch {
diff --git a/txfee_test.go b/txfee_test.go
index ab34741..82e6413 100644
--- a/txfee_test.go
+++ b/txfee_test.go
@@ -60,6 +60,8 @@ func TestEstimateTxSize(t *testing.T) {
 
 func TestEstimateTxSize_VIN_1_P2PKH(t *testing.T) {
 	{
+		// 这个就是从官方包里拷贝的
+		// https://github.com/btcsuite/btcwallet/blob/b4ff60753aaa3cf885fb09586755f67d41954942/wallet/txsizes/size_test.go#L145
 		const txHex = "0100000001a4c91c9720157a5ee582a7966471d9c70d0a860fa7757b4c42a535a12054a4c9000000006c493046022100d49c452a00e5b1213ac84d92269510a05a584a4d0949bd7d0ad4e3408ac8e80a022100bf98707ffaf1eb9dff146f7da54e68651c0a27e3653ec3882b7a95202328579c01210332d98672a4246fe917b9c724c339e757d46b1ffde3fb27fdc680b4bb29b6ad59ffffffff02a0860100000000001976a9144fb55ee0524076acd4c14e7773561e4c298c8e2788ac20688a0b000000001976a914cb7f6bb8e95a2cd06423932cfbbce73d16a18df088ac00000000"
 
 		mstTx, err := NewMsgTxFromHex(txHex)
diff --git a/utils.go b/utils.go
index 70d5199..55a09c3 100644
--- a/utils.go
+++ b/utils.go
@@ -12,7 +12,6 @@ import (
 	"github.com/btcsuite/btcd/rpcclient"
 	"github.com/btcsuite/btcd/txscript"
 	"github.com/btcsuite/btcd/wire"
-	"github.com/btcsuite/btcwallet/wallet/txrules"
 	"github.com/pkg/errors"
 )
 
@@ -79,36 +78,6 @@ func MustGetPkScript(address btcutil.Address) []byte {
 	return pkScript
 }
 
-// IsDustOutputBtc 检查是不是灰尘输出，链不允许灰尘输出，避免到处都是粉尘
-func IsDustOutputBtc(netParam *chaincfg.Params, address string, amount int64, dustLimitCoin float64, feePerKb btcutil.Amount) (bool, error) {
-	dustLimitAmount, err := btcutil.NewAmount(dustLimitCoin)
-	if err != nil {
-		return false, errors.WithMessage(err, "wrong dust limit coin to amount")
-	}
-	if btcutil.Amount(amount) < dustLimitAmount { //当小于硬性灰尘数量时，就肯定是灰尘的
-		return true, nil
-	}
-	pkScript, err := GetAddressPkScript(address, netParam)
-	if err != nil {
-		return false, errors.WithMessage(err, "wrong address->pk-script")
-	}
-	output := wire.NewTxOut(amount, pkScript)
-	isDust := txrules.IsDustOutput(output, feePerKb)
-	return isDust, nil
-}
-
-// IsDustOutputDoge 根据 https://github.com/dogecoin/dogecoin/blob/master/doc/fee-recommendation.md 这个看到只有两个规则
-func IsDustOutputDoge(amount int64, dustLimitCoin float64) (bool, error) {
-	dustLimitAmount, err := btcutil.NewAmount(dustLimitCoin)
-	if err != nil {
-		return false, errors.WithMessage(err, "wrong dust limit coin to amount")
-	}
-	if btcutil.Amount(amount) < dustLimitAmount { //当小于硬性灰尘数量时，就肯定是灰尘的
-		return true, nil
-	}
-	return false, nil
-}
-
 // NewInputOuts 因为 SignParam 的成员里有 []*wire.TxOut 类型的前置输出字段
 // 但教程常用的是 pkScripts [][]byte 和 amounts []int64 两个属性
 // 因此这里写个转换逻辑
diff --git a/utils_test.go b/utils_test.go
index 7d8b458..33004a4 100644
--- a/utils_test.go
+++ b/utils_test.go
@@ -9,41 +9,6 @@ import (
 	"github.com/yyle88/gobtcsign/dogecoin"
 )
 
-func TestIsDustOutputDoge(t *testing.T) {
-	const dustLimitCoin = 0.001 //THE HARD DUST LIMIT IS SET AT 0.001 DOGE - OUTPUTS UNDER THIS VALUE ARE INVALID AND REJECTED. (https://github.com/dogecoin/dogecoin/blob/master/doc/fee-recommendation.md)
-	{
-		const amount = 500
-		isDust, err := IsDustOutputDoge(amount, dustLimitCoin)
-		require.NoError(t, err)
-		require.True(t, isDust)
-		t.Log("amount:", amount, "IS DUST IN DOGE")
-	}
-	{
-		const amount = 100000
-		isDust, err := IsDustOutputDoge(amount, dustLimitCoin)
-		require.NoError(t, err)
-		require.False(t, isDust)
-		t.Log("amount:", amount, "IS NOT DUST IN DOGE")
-	}
-}
-
-func TestIsDustOutputBtc(t *testing.T) {
-	amount := int64(100000)
-	for {
-		const address = "1MAgFFbMpgx6hTPvK3HY348Bbnwk6RFHm5"
-		const feePerKb = 1234 * 1000 //假设手续费是这个数
-		const dustLimitCoin = 546e-8 //BTC CHAIN: CONSIDERS ANYTHING BELOW 546 SATOSHIS (PARTS OF A BITCOIN) TO BE DUST.
-		isDust, err := IsDustOutputBtc(&chaincfg.MainNetParams, address, amount, dustLimitCoin, feePerKb)
-		require.NoError(t, err)
-		if !isDust {
-			break
-		}
-		amount++
-	}
-	t.Log("amount:", amount, "IS NOT DUST IN BTC")
-	t.Log("amount:", amount-1, "IS DUST IN BTC")
-}
-
 func TestGetAddressPkScript(t *testing.T) {
 	netParams := dogecoin.TestNetParams
 	pkScript := caseGetAddressPkScript(t, "nXMSrjEQXUJ77TQSeErpJMySy3kfSfwSCP", &netParams)
diff --git a/verifytx.go b/verifytx.go
index 1a95662..a02482c 100644
--- a/verifytx.go
+++ b/verifytx.go
@@ -117,13 +117,24 @@ func VerifySignV2(msgTx *wire.MsgTx, inputList []*VerifyTxInputParam, netParams
 }
 
 func VerifySignV3(msgTx *wire.MsgTx, inputsItem *VerifyTxInputsType) error {
-	inputFetcher, err := txauthor.TXPrevOutFetcher(msgTx, inputsItem.PkScripts, inputsItem.InAmounts)
+	prevScripts := inputsItem.PkScripts
+	inputValues := inputsItem.InAmounts
+
+	return VerifySignV4(msgTx, prevScripts, inputValues)
+}
+
+// VerifySignV4 这是验证签名的函数，代码主要参考这里
+// https://github.com/btcsuite/btcwallet/blob/b4ff60753aaa3cf885fb09586755f67d41954942/wallet/createtx.go#L503
+// 这个 github 官方包 是非常重要的参考资料
+// https://github.com/btcsuite/btcwallet/blob/master/wallet/createtx.go
+func VerifySignV4(msgTx *wire.MsgTx, prevScripts [][]byte, inputValues []btcutil.Amount) error {
+	inputFetcher, err := txauthor.TXPrevOutFetcher(msgTx, prevScripts, inputValues)
 	if err != nil {
 		return errors.WithMessage(err, "wrong cannot-create-pre-out-cache")
 	}
 	sigHashCache := txscript.NewTxSigHashes(msgTx, inputFetcher)
 
-	inputOuts := NewInputOutsV2(inputsItem.PkScripts, inputsItem.InAmounts)
+	inputOuts := NewInputOutsV2(prevScripts, inputValues)
 
 	return VerifySign(msgTx, inputOuts, inputFetcher, sigHashCache)
 }