Abstract: By taking ultra-high molecular weight polymer in Daqing oilfield as an example,through the indoor experiment,the matching characteristics between oil displacement polymer and rock pore throat were studied.The different oil displacement effect of different oil displacement characteristics in the interlayer heterogeneity model,and the influence of the distribution characteristics of each layer stage were given,which further verified the compatibility between polymer thread size and rock pore throat size.The study results indicate when the rock pore throat radius values and polymer molecules in thread size match well,the polymer in porous media has a better oil displacement effect and streaming characteristics,the polymer and rock pore structure has good matching characteristics.