Abstract: Surface modification is the treatment technology that makes the tailored surface microstructure different from that of the matrix, which can efficiently control the mechanical properties of the material surface. Therefore, the surface modification can improve the microstructure of the cemented carbides, effectively avoid the limitation of the homogeneous structure cemented carbides on the microstructure and macroscopic properties, and provide the technical scheme for the preparation of the high performance inhomogeneous structure cemented carbides. Due to the late start of the surface modification research and a mass of surface modification methods, the selection of surface modification methods and the modification mechanism are still not clear. The material system, preparation mechanism, microstructure, and mechanical properties of the graded cemented carbides obtained by chemical surface modification were summarized in this paper, the methods and functions of the graded cemented carbide coatings obtained by physical surface modification were concluded. The application and research progress of the surface modification used for the cemented carbides were analyzed to provide the reference for the preparation of the cemented carbides with high wear resistance and good fracture toughness.