In order to solve the problem of low hardness and poor wear resistance of 40CrNiMoA steel, a heat treatment process was designed, and three different quenching mediums were used, including water, salt solution and oil, to carry out high-frequency quenching and low-temperature tempering heat treatment of 40CrNiMoA steel. The HV-2000 Vickers hardness tester was used to test the surface hardness of the sample after heat treatment, and the SFT-2M ball-disc friction and wear testing machine was used to test its wear resistance. The results show that when the quenching medium was salt solution, the tempered martensite was smaller, and the surface hardness of the specimen after heat treatment was the highest, reaching 431.2 HV_0.2, and the wear was the smallest. After quenching in salt solution, fine tempered martensite can be obtained, resulting in increased hardness of 40CrNiMoA steel, less wear of the specimen and enhanced wear resistance.