Abstract: When the main reservoir groups of Daqing Oilfield are after polymer flooding,the mid and high molecular polymer in class II and III reservoirs will have poor adaptability to some reservoirs,injected solution will flow into other reservoirs with good property and connectivity,and the thin and poor layers of them are hardly produced.To solve these problems and improve the ultimate recovery rate,this paper puts forward the polymer separate injection technology with separate mass and pressure.It introduces the molecular regulator and pressure regulator,which will be applied to low-permeability and high-permeability reservoirs separately,so as to realize the dual control on molecular weight and injection rate.Based on keeping the polymer flooding effect of high-permeability reservoirs,the molecular is degraded and shorn to increase the pore volume that permits the polymer molecular to enter into the low-permeability reservoirs.The data obtained from the field test show that the polymer injection technology with separate mass and separate pressure can more increase the profile producing degree than the conventional layering polymer flooding technology.It can meet the demand of the class Ⅱ and Ⅲ reservoir in the oilfield for polymer separate injection.