diff --git a/contracts/SmartRoute/SmartSwap.sol b/contracts/SmartRoute/SmartSwap.sol
index 9603d73..7896913 100644
--- a/contracts/SmartRoute/SmartSwap.sol
+++ b/contracts/SmartRoute/SmartSwap.sol
@@ -72,12 +72,12 @@ contract SmartSwap is Ownable {
             if(curDirection == 0){
                 address curDodoBase = IDODO(curDodoPair)._BASE_TOKEN_();
                 uint256 curAmountIn = IERC20(curDodoBase).balanceOf(address(this));
-                IERC20(curDodoBase).approve(curDodoPair,curAmountIn);
+                IERC20(curDodoBase).universalApprove(curDodoPair,curAmountIn);
                 IDODO(curDodoPair).sellBaseToken(curAmountIn, 0, "");
             }else {
                 address curDodoQuote = IDODO(curDodoPair)._QUOTE_TOKEN_();
                 uint256 curAmountIn = IERC20(curDodoQuote).balanceOf(address(this));
-                IERC20(curDodoQuote).approve(curDodoPair,curAmountIn);
+                IERC20(curDodoQuote).universalApprove(curDodoPair,curAmountIn);
                 uint256 canBuyBaseAmount = dodoSellHelper.querySellQuoteToken(curDodoPair,curAmountIn);
                 IDODO(curDodoPair).buyBaseToken(canBuyBaseAmount, curAmountIn, "");
             }
@@ -112,10 +112,10 @@ contract SmartSwap is Ownable {
 
         if (fromToken != ETH_ADDRESS) {
             smartApprove.claimTokens(fromToken, msg.sender, address(this), fromTokenAmount);
-            fromToken.approve(approveTarget, fromTokenAmount);
+            fromToken.universalApprove(approveTarget, fromTokenAmount);
         }
 
-        (bool success, ) = to.call{value: msg.value, gas: gasSwap}(callDataConcat);
+        (bool success, ) = to.call{value: fromToken == ETH_ADDRESS ? msg.value : 0, gas: gasSwap}(callDataConcat);
 
         require(success, "Contract Swap execution Failed");
 
diff --git a/contracts/lib/UniversalERC20.sol b/contracts/lib/UniversalERC20.sol
index 7005a5b..a1208b2 100644
--- a/contracts/lib/UniversalERC20.sol
+++ b/contracts/lib/UniversalERC20.sol
@@ -43,7 +43,18 @@ library UniversalERC20 {
 
     function universalApprove(IERC20 token, address to, uint256 amount) internal {
         if (token != ZERO_ADDRESS && token != ETH_ADDRESS) {
-            token.safeApprove(to, amount);
+            if (amount == 0) {
+                token.safeApprove(to, 0);
+                return;
+            }
+
+            uint256 allowance = token.allowance(address(this), to);
+            if (allowance < amount) {
+                if (allowance > 0) {
+                    token.safeApprove(to, 0);
+                }
+                token.safeApprove(to, amount);
+            }
         }
     }
 
diff --git a/deploy-detail.txt b/deploy-detail.txt
index 94504ae..0f0c76c 100644
--- a/deploy-detail.txt
+++ b/deploy-detail.txt
@@ -1,8 +1,8 @@
 ====================================================
 network type: live
-Deploy time: 2020/11/15 下午3:25:21
+Deploy time: 2020/11/16 上午10:26:34
 Deploy type: Smart Route
 SmartApprove Address:  0xe380Ad3181A69BF92133D2feb609867c4adC61eA
 DODOSellHelper Address:  0x533da777aedce766ceae696bf90f8541a4ba80eb
-SmartSwap Address:  0xf40be68442e8bcf900FED714246f99BE556345e7
-SmartApprovce setSmartSwap tx:  0xfd22c5e3ede777d21f0a0d2d8a64ccee584cc43fa2b72113c97360408c974beb
+SmartSwap Address:  0xcD8392A57ED2fBD6440037E52F176c26dEFc0ba4
+SmartApprovce setSmartSwap tx:  0x35eccc657ee0d473b6e58324123d3da568ce12389fedff914a8dada563b35b3a