Abstract: When the polymer injecting oilfield enters the middle and late stage of polymer injection, the formation of polymer channeling channel will seriously reduce the polymer flooding effect, while affected by development investment, platform space and other restrictions, it is difficult for the offshore oilfield to implement multi-round profile control to mitigate the impact of polymer injection. In order to further improve the effect of oil increase by chemical flooding in offshore polymer injecting oilfields, the physical simulation experiment of J oilfield in Bohai sea shows that the polymer enhanced foam flooding system can effectively block the flow channel of hyperpermeability layer and improve the utilization degree of low-permeability layer.The injection slug of the composite system has a stronger sealing effect on the hyperpermeability layer and improves the overall oil displacement effect. Compared with the middle and high water cut stage, the higher water cut stage can be converted into polymer enhanced foam flooding, and the enhanced oil recovery can be achieved.