Abstract: Some theories and methods of structure mechanics were applied to simulate the efficiently welding deformation.Since the seam size is too small to contribute itself to the strengthen of huge construction,it can be replaced by residual strain and stress in complicated welded structure in order to improve the quality of ANSYS meshing and save calculating time.Residual stress and strain distributions obtained by thermal elastic and plastic finite ANSYS method were analyzed,respectively.The principle of virtual work and the displacement method were used to load the residual stress and strain of weld seam on the corresponding node in welded structure,which made the stress and strain loading process more convenient and useful.The deformation of welded structure in simulation was proved by comparing the experience data.It was proved that the method to simulate the welding deformation based on the principle of virtual work and the displacement method can be used to predict the deformation of complicated welded structure.