Abstract: At present, the contradiction between injection and production is becoming more obvious in S-1 block of BZ oilfield. The large accumulative water injection deficit leads to the decline of formation pressure, low formation pressure and poor oilfield development effect. Therefore, by using numerical simulation and Logisitic life cycle mathematical model, the reasonable injection-production ratio of oilfield under different water cut conditions was studied and the drawing plates of the reasonable injection-production ratio under different water cut conditions were established. The results show that the reasonable injection-production ratio of S-1 block obtained by Logisitic life cycle mathematical model is1.22, and the reasonable injection-production ratio obtained by numerical simulation model is 1.2～1.3.