Abstract: A coupled thermal-mechanical FE (finite element) model of 7A52 aluminum alloy TANDEM welding and a simplified FE model for single-GCr15 shot impact simulation were developed separately. The element size of welded joint region which was impacted by shots was amplified reasonably. Based on the premise,the numerical results would not be affected by this simplification. The computational results of welding residual stress were obtained,and the influences of ball's dimension and impact velocity on induced residual stresses were analyzed subsequently. On the basis,the coupling computation of residual stress field in aluminum alloy welded joint and the shot peening treatment were performed by means of data transfer based on the standard and explicit solver of ABAQUS software. The computational results showed that the residual stresses on the surface and depth direction of welded joint were improved remarkably after shot peening.