Abstract: Two pieces of 200 mm×100 mm×6 mm S30408 stainless steel plates were butt welded by manual argon arc welding. The residual stress distribution near the weld and the effect of shot peening on the residual stress field were studied by means of test and simulation.The results show that there is a large residual tensile stress near the weld before shot peening, which is symmetrically distributed along the weld centerline.The maximum transverse residual tensile stress is 138 MPa, and the maximum longitudinal residual tensile stress is 295 MPa. Comparing the residual stress on the sample surface before and after shot peening with shot velocity of 100 m/s, shot diameter of 0.5 mm, coverage rate of 100%, it is found that shot peening can eliminate residual tensile stress and introduce high compressive stress. A random distributed shot peening model was established for numerical simulation, and the simulation results are in good agreement with the experiment.By simulating the residual stress distribution under different shot velocity and diameter, it is found that the residual compressive stress on the surface and subsurface of the specimen increases with the increase of the shot velocity from 80 m/s to 160 m/s or the diameter from 0.3 mm to 1 mm.