Abstract: The finite element model of welding in plate dryer was established. The residual deformation of different schema including forward welding, facing welding, backward welding, with total fifteen kinds of welding sequences were numerical simulated with the method of segmented moving heat source.The results show that the welding deformation of workpiece is bulging upward along the center, the welding deformation gradually increases from the outside tothe inside, the maximum deformation is in the inner part. The residual deformation of backward welding with aninterval of three rows is the minimum, which is 68% of that with forward welding with three rows interval and it is also 58.8% of the maximum residual deformation the fifteen kinds of welding sequences. The relative quantity of welding deformation in each optimized schemes is decreased appreciably while the diameter of plate dryer is bigger and the interval welding time of each rows is longer, the cooling time of each rows can be therefore shortened properly.