Abstract: This paper simulated the cyclic cumulative plastic deformation of SA508-3 steel based on damage-coupled constitutive model at 200℃ temperature. Firstly, a series of uniaxial tensile and cyclic loading experiments were conducted to determine the parameters of the damage-coupled constitutive model. Based on the damage-coupled constitutive model, monotonic loading and cyclic plastic deformation were simulated for SA508-3 steel. Compared to the simulation results by Chaboche model, the damage-coupled constitutive model can give a better simulation for monotonic tensile behavior and cyclic softening behavior of 508-3 steel under strain and stress control, agree well with the experimental results, and build the foundation for the cumulative plastic deformation simulation of nuclear equipments made with 508-3 steel.