Abstract: Based on the thermo-elastic-plastic theory and the SYSWELD finite element analysis software, the finite element model of the scanning laser wire filling multi-layer and multi-pass welded joint of 5A06 aluminum alloy was established. The simulated results of temperature field, residual stress and deformation were studied and verified by experiments. The results show that the heat input of each pass of the narrow gap scanning laser wire filling welding is small, which cannot lead to the grain growth in heat affected zone. The maximum transverse residual stress appears in the area of the weld metal near the lower surface, which is about 130 MPa. The longitudinal residual stress of weld metal near the upper surface is the largest. The residual stress value in the thickness direction is small. By comparing with the measured values, the simulated values of residual stress and deformation are basically consistent with the measured values, which means the residual stress distribution and post-welding deformation of the joints can be predicted and analyzed.