In order to investigate the influence of welding residual stress on fatigue crack growth at different initial angles, the thermal elastic-plastic finite element method was used to calculate the welding residual stress, the stress intensity factor and the fatigue life and crack growth rate when the crack depth reached 1mm were combined with the linear elasticity and Paris formula. The results show that; The initial stress intensity factor decreases with the increase of the initial crack Angle, and increases during the crack growth, and then remains stable. The fatigue life of the crack with the initial Angle of 90° is the shortest, and special vigilance is needed because of its short surface length. When the crack depth reaches the critical size, the initial Angle of 0° is elliptic, and with the increase of the initial Angle, the crack propagation becomes circular. With the crack propagation, the influence of welding residual stress decreases and the difference of crack propagation rate at different initial angles decreases and then tends to be stable. The joint action of residual stress and external load can significantly increase the crack growth rate. At the same time, the engineering suggestions to reduce welding residual stress and improve fatigue life are given based on the calculation results, which can provide some reference for the design of welded structural parts such as pressure vessels.