Abstract: Confirming the effect of separate layer injection is an important content of polymer flooding development prediction. Aiming at the problems of less methods of confirming the effect of separate layer injection and the big difficulty in process of index prediction, the numerical simulation method is used to calculate the impact of separate layer injection on the ultimate recovery during the different water cut stages, and the best proportion of solution injection rate is calculated in low permeability layers. The effect of layered polymer flooding in Daqing oilfield is systematically analyzed, and the influence of separate layer injection on comprehensive water cut and enhanced oil recovery is obtained, which provides a basis for predicting the effect of polymer flooding in crude oil development planning.