diff --git a/server/light_backtask/service/vip.go b/server/light_backtask/service/vip.go
index 5efc8000..75c61ea2 100644
--- a/server/light_backtask/service/vip.go
+++ b/server/light_backtask/service/vip.go
@@ -142,8 +142,9 @@ func (this *vip) RecalcEsCecConvert(accountAddress string) error {
 			if nowTime > lastDeposit.chainTimestamp {
 				bnPassTime := new(big.Int).SetInt64(int64(nowTime - lastDeposit.chainTimestamp))
 				bnTotalTime := new(big.Int).SetInt64(int64(365 * 24 * 2600))
-				bnRate := bnPassTime.Div(bnPassTime, bnTotalTime)
-				bnTotal.Mul(bnTotal, bnRate)
+				bnTmp := bnTotal.Mul(bnTotal, bnPassTime)
+				bnInterest := bnTmp.Div(bnTmp, bnTotalTime)
+				bnTotal = bnTotal.Sub(bnTotal, bnInterest)
 			}
 		}
 		bnAmount, _ := new(big.Int).SetString(val.depositAmount, 10)