Abstract: Currently polymer flooding target of Daqing oilfield has been converted to the second grade reservoirs with lower properties and much interlayer contradiction,and conventional separate injection technology is facing new problems.The polymer single pipe multizone separate qualitative separate pressure injection technology realizes relative molecular weight and concentration going down.At the same time,it also guarantees enough injection rate.High permea-bility reservoir needs to control injection rate while reducing viscosity loss rate.With obvious effect in field test,it can meet the demand of the second grade reservoirs for polymer separate injection.