In order to improve the measurement accuracy of welding residual stress, welding residual stress is corrected by using shape-changed strength ratio and the method of discretizing joint material property on the base of residual stress test of 2219-T87 aluminum alloy TIG welding joint. Simultaneously, the effects of plastic deformation around holes and joint strength mismatch on welding residual stress estimation are studied separately. The results show that the method of estimating welding residual stress which considers both plastic deformation around hole and joint strength mismatch can reduce 39.8% error through contrasting with linear elastic estimation method; The way of considering the effect of joint strength mismatch and plastic deformation can reduce 40.6% error when the distance between the measuring point and welding seam is less than 8mm; And the joint strength mismatch effect on welding residual stress estimation can be ignored when the distance between the measuring point and welding seam is more than 8mm.