Due to the influence of reservoir porous media shear and other factors，the viscosity-concentration relationship of polymer solution obtained by experimental methods is difficult to directly be applied in numerical simulations. At present，the commonly used empirical or analogical methods have large errors，and there is still a lack of effective numerical simulation methods for determining the viscosity-concentration relationship in polymer flooding. In this paper，the experiment of the influence law of polymer flooding was designed and carried out，and the numerical simulation model of polymer flooding core was established to fit the experimental results. The viscosity-concentration relationship of polymer flooding numerical simulation under different temperature，salinity and permeability conditions was determined. The prediction model of polymer viscosity-concentration relationship adjustment was established，and then the method of determining the viscosity-concentration relationship of polymer flooding numerical simulation was formed. Research results was shown that using the proposed method to determine polymer viscosity concentration relationship data，the fitting error of polymer flooding water content was 1.81%，which was 7.42% lower than that of the existing empirical. The accuracy of polymer flooding numerical simulation was improved，which provided reliable parameters and references for numerical simulation of polymer flooding.