Abstract: The numerical simulation of stress distribution in aluminum-steel dissimilar metal welded joint during cold metal transition (CMT) welding was carried out by using ABAQUS finite element software. The variation law of stress distribution was analyzed and verified by experiments. The results show that at different welding times, the von Mises stresses unsymmetrically distributed at steel plate side and Al alloy plate side in the welded joint. And the stresses at Al alloy plate side were smaller than those at steel plate side. During the welding process, the longitudinal stress near the weld changed from the compressive stress into tensile stress, while the lateral stress at the welding initiating stage was tensile stress, then changed into compressive stress and then tensile stress. The longitudinal residual tensile stresses reached the largest values in the heat affect zone near the side of steel plate and Al alloy plate, which were 125 MPa and 208 MPa, respectively, while the peak values of lateral residual compressive stress were almost the same at both sides, which was about 80 MPa. The goodness-of-fit between the simulated and test results of residue stress distribution was 0.75, indicating the accuracy of the simulation results.