Abstract: Based on the thermal elastic-plastic analysis method of ABAQUS finite element software, the residual stress and residual deformation of 32 mm thick Q345qD steel butt joint under gas metal arc welding (GMAW) are studied in this paper. Combined with experimental test and numerical simulation, the effects of four different welding sequences on the residual stress distribution and residual deformation of butt joint are studied. The element birth and death is used to simulate the filling of deposited metal, and the volume heat source with double ellipsoid distribution is used to realize the movement of welding arc. The results show that the numerical simulation results are in good agreement with the experimental results. The change of welding sequence has little effect on the temperature field; compared with that of welding the other side after welding, the overall stress level of transverse residual stress by alternating welding on both sides is smaller, and the maximum value is reduced from 356 MPa to 278 MPa, which is reduced by 21.91%; while the overall stress level of longitudinal residual stress by alternating welding on both sides is larger, and the maximum value of longitudinal residual stress is increased from 303 MPa to 368 MPa, which is increased by 21.45%. The deformation in the thickness direction of alternating welding on both sides is smaller, and the maximum value is reduced from 1.67 mm to 0.04 mm, which is reduced by 97.60%.