Abstract: GCr15 bearing steel was treated by quenching+tempering, quenching+tempering+deep cryogenic, quenching+deep cryogenic+tempering, quenching+tempering+deep cryogenic+tempering treatment, respectively, and the influence of deep cryogenic treatment on microstructure, hardness and wear resistance of GCr15 bearing steel was discussed. The results show that comparing with that treated by traditional quenching+tempering treatment, the content of retained austenite in the samples treated by the process with addition of deep cryogenic treatment decreased, the hardness increased and wear resistance was improved. The content of retained austenite in the sample treated by quenching+deep cryogenic+tempering was the lowest, the hardness was the highest, the wear resistance was the best, and the wear loss was reduced by 6% compared with that treated by quending and tempering treatment. The deep cryogenic treatment improved the fatigue wear resistance and abrasive wear resistance of GCr15 bearing steel.