As the sandwich panel structure is simple and relatively lighter with considerable strength

it has great application prospect in the shipbuilding industry. Using the laser welding to fabricate the steel sandwich panel is the preferred manufacturing technology.As the T-joint structure is the base welding unit of the sandwich structure

this paper has set up a T-joint welding platform based on laser welding. On the basis of the experimental results

a new mixed heat source model was proposed. The heat flux distribution during laser welding could be accurately described by the mixed heat source model. Through laser welding experiment and FEM calculation

the welding deformation and residual stresses of the sandwich structure were analyzed. Besides

the influence factors on the welding deformation and residual stresses were also discussed

finding that the welding deformation was significantly decreased by using laser welding

but the residual stress was still at high level.