Polymer microsphere is a kind of water-absorbable and swellable gel resin based on polyacrylamide, which has achieved good precipitation and oil-increasing effects in oil field profile control and flooding. As the mining focus gradually shifts to low permeability, medium low permeability and high temperature reservoirs, the particle size, slow swelling performance, temperature resistance, salt resistance and shear resistance of polymer microsphere have become important research topics. In this paper, the structure characteristics and structure-activity relationship of different polymeric microspheres in recent years were reviewed. The reservoir conditions applicable to different polymer microspheres were summarized, and the factors affecting the particle size and swelling performance of polymer microspheres were analyzed. The profile control and flooding mechanism of polymer microspheres was discussed, and the research direction of polymer microspheres was prospected: In order to solve the problems of polymer microspheres, such as the few reports about nanometer scale, the fast expansion rate at high temperature and the single displacement mechanism, it is necessary to deepen the research on the swelling mechanism and viscoelastic mechanism of polymer microsphere, and optimize the synthesis conditions of inverse microemulsion method, develop nanometer polymer microsphere with core-shell structure, and cooperate with other chemicals, so as to broaden the application field of polymer microspheres in low permeability, medium low permeability and high temperature reservoirs.