Abstract: Objective The aim is to improve stress and deformation in the manufacturing storage tank process, to enhance the quality of storage tank stability and assembling precision. Methods For the numerical simulation of welding deformation of thin-walled storage tank structures, the method of result data transmission was adopted to achieve continuous numerical simulation of the manufacturing process, to avoid the problem of poor accuracy of single-process simulation results. This study conducted numerical simulations of the roll bending forming of a 2 mm thick 2219 aluminum alloy storage tank and subsequent tungsten inert gas welding (TIG), to obtain the distribution patterns of stress and deformation during the assembly process. It particularly investigated the effect of welding sequence on the assembly welding deformation of the storage tank. Results The results indicated that stress accumulation during the cylindrical shell section roll bending process led to concentrated residual welding stresses on the upper and lower sides of cylindrical shell section, while welding deformation was concentrated at the upper and lower forked rings of storage tank. The longitudinal weld of cylindrical shell section was welded with a zoned symmetrical approach, while the circumferential welds of storage tank were welded symmetrically from the top and bottom simultaneously, starting with the forked ring and the box bottom ring, reducing the peak deformation of cylindrical shell section and storage tank to 0.65 mm and 0.45 mm. Conclusion The welding deformation of thin-walled storage tank can be effectively controlled in the assembly process by reasonably planning welding sequence.