Abstract: For 2A14 aluminum alloy saddle-shaped joint between the flange and the wall of a storage tank, the three-dimensional saddle-shaped joint between the flange and the wall was established by using the thermo-mechanical coulped simulation method, and the postweld deformation of the wall-flange structure under different welding powers and welding speeds were calculated.The results show that reducing the welding power and increasing the welding speed can effectively reduce the welding heat input, and reduce the welding deformation of the wall-flange structure.When the back welding power and speed are 3000 W, 3.33 mm/s respectively, and the capping welding power and speed are 4270 W, 1.67 mm/s respectively, the welding residual deformation of the flange is no more than 1.5 mm and the deformation of sealing groove on the flange is no more than 0.6 mm.