Abstract: The characteristics of welding residual stresses are of great significance for the safe operation and the structural improvement of all-welded ball valves. Based on the finite element software ABAQUS, the temperature field, stress field and displacement field of the full-welded ball valves have been simulated with the three typical models of the T-joint welding, plate butt welding and pipe butt welding as the examples. The results show that the calculation error of the nonlife-and-death element method is about 10% higher than that of the life-and-death element method, but the calculation time is shortened by 41% to 57%. The welding residual stresses of the ball valves are concentrated at the joint position of the welds and the base material. The circumferential and the axial residual stresses on the outer surface of the weld affected areas of the ball valves are tensile, which gradually transit to be compressive along the depth direction of the welds to the inner surface. In addition, the circumferential residual stresses accumulate along the welding direction, and the maximum compressive stresses generally occur at the end of the welds while the axial stresses are concentrated in the affected area of the intermediate body in the ball valves. Under a combined action of the circumferential and axial stresses, both of the right body and the intermediate body of the ball valves shrink towards the weld areas, and the right body of the ball valves deforms obviously, without obvious impact on the opening and closing movement, as well as the sealing performance of the ball valves.