Abstract: When come into the water cut stage,flooding degree in oil layer increase gradually,which causes the existence of different levels of water flooded layers,makes geologic & reservoir condition complicated further,brings great challenge for the adjustment well's production capacity forecast. The study shows that the water cut rate of adjustment well, and the production capacity of different water cut stage,are the keys for forecasting adjustment well's production.In this article,we applied the water flooded layer thickness weighting method,analogy method,numerical simulation method to predict water cut,used dimensionless productivity index method to predict reservoir oil production capacity and established a set production capacity forecast way of adjustment wells in different water cut stage.Verified by the production data of oilfield,the forecast result is authentic,the method is practical and applicable for the adjustment well's production capacity forecast in different water cut stage.