Abstract: During the process of the truck side-walls welding, buckling deformation is caused by the shrinkage force in the weld seams.It is difficult to predict and control the distortion.The buckling deformation which not only reduces the strength but also affects the smoothness and the beauty of thin-plate.The welding distortion of the truck side-wall was studied using inherent strain as an equivalent load.The results show that the predicted results is consistent with the measured data.Based on the simulation model, the different factors involved in the design and welding affecting the distortion were investigated using the orthogonal design.The optimal design is presented, which provides reliable theoretical references for thin-plate welding deformation controlling of the truck side-walls.