Abstract: The hot compression test of SA508-3 steel was carried out on Gleeble1500D thermal simulation testing machine, and the hot deformation behavior of the material was studied. The test parameters were the temperature of 800-1200℃, the strain rate of 0.001-1 s^-1, and the deformation amount of 45%.The modified constitutive model of SA508-3 steel was established by using the strain compensation method. The model is obtained based on the Arrhenius constitutive model which comprehensively considers the influence of the deformation temperature and strain rate on the flow stress and the introduction of strain on each parameter in the model. By comparing the correlation coefficient (R)and the average relative error (AARE) between the stress prediction value of the revised constitutive model and the true value of the test, the R is 0.996 and the AARE is 4.89%, which proves that the revised model has high accuracy.