Abstract: Different solid solution heat treatment process tests of ATI425 alloy bars were conducted, and the effects of solid solution temperature and insulation time on its microstructure and mechanical properties were studied. The results show that as the solution temperature increases from 870℃ to 930℃, the tensile strength of the alloy decreases from 1149 MPa to 1046.5 MPa, and the elongation and reduction of area are always on the rise. The effect of room temperature performance is less than that of solid solution temperature, and the holding time is controlled at 90 min, and the uniformity of the microstructure is relatively good.