Abstract: Experimental study and thermal elastic-plastic finite element method(FEM) of plate surfacing were carried out for 304L stainless steel,and rationality of assumed material properties under high temperature in calculation was verified by consistency of experimental results and numerical simulation results.On this basis,thermal elastic-plastic FEM was applied to welding of dome and cylinder shell of independent liquid tank of 304L stainless steel LNG carrier,and structural welding deformation was predicted successfully.