In order to solve the problem of wear failure during the service of the hot grinding discs, the microstructure changes and wear resistance of high-carbon hot grinding discs during quenching and tempering were investigated. Taking high chromium high carbon cast iron as the research object, the microstructure and performance of the heat-treated specimen were studied by means of metallographic microscope, X-ray diffraction, hardness tester and wear tester. The results show that the original microstructure consists of primary (Cr，Fe)7C3, eutectic (Cr，Fe)7C3, martensite and austenite. When tempering at a lower temperature, the carbides are not obviously changed and the matrix is tempered martensite and austenite; with the increase of temperature, the carbides gradually increases and the tempered martensite gradually decreases; the tempered martensite disappears and the matrix microstructure changes to ferrite and austenite over 450 ℃. The hardness first decreases slightly, then increases and finally decreases, and the maximum value is 63.4HRC at 450 ℃. The wear resistance of uniformly distributed carbides is increased by 2.53 times. The results of the effect of quenching and tempering process on the microstructure and wear resistance of high-carbon hot grinding disc provide a theoretical basis for improving the wear resistance and service life of high-carbon hot grinding disc.