Abstract: Laser welding joints of 75Cr1 steel and SPHC low-carbon steel were prepared, and the welds were preheated and subjected to the first annealing treatment by using a heat treatment device integrated with the welding machine. Then, the weld seam underwent secondary annealing using an additional induction heater. By adjusting the heating power and time, the influence of different secondary annealing processes on the microstructure and properties of the weld seam was investigated. The results show that with the increase of the heat power and the prolongation of the heat treatment time, the cupping bulge performance of the welding joint increases, additionally, the maximum microhardness at the heat-affected zone (HAZ) at the 75Cr1 side decreases from 770 HV under the first annealing treatment to about 300 HV. The microstructure at the position of maximum microhardness transforms from martensite to tempered martensite, sorbite, and then pearlite.