Abstract: The influence of different tempering conditions on fatigue properties of H13 steel for disc spring was studied by means of uniaxial tensile compression hydraulic test machine and scanning electron microscope. It can be seen from the fatigue S-N curve that the fatigue properties of H13 steel can be significantly improved by the secondary tempering process under different external stress conditions. Fatigue fracture analysis shows that the proportion of the instantaneous fault area of the secondary tempered sample is relatively small, which indicates that it has better anti-fatigue performance under high stress conditions. In addition, the inclusion size of the sample is reduced after secondary tempering, which is helpful to reduce the initiation of fatigue cracks. According to the amplitude of stress field intensity factor calculated by the improved Tanaka-Akiniwa model, the value of secondary tempering is smaller under different stress amplitude, which further proves that the secondary tempering process can effectively reduce the risk of fatigue failure. Therefore, after holding H13 steel at 1000℃ for 20min, quenching oil,tempering at 560℃ for 120min, air cooling to room temperature, and then carrying out the tempering process with the same heat treatment parameters is a more reasonable heat treatment process, which can significantly improve the fatigue properties of H13 steel.