Abstract: A thermo-mechanical coupling model of TC4 titanium alloy skin-stringer T joint manufactured by double-laser beam bilateral synchronous welding was established. The residual stress of the joint after welding under three welding sequences was obtained, and the variation of residual stress was studied. The results show that the residual stress of the T-joint in the cross section reaches the peak value in the weld center, and it mainly manifests as longitudinal residual stress, and a triangle like zone with large transverse residual stress forms in the weld center. Far away from the weld area, the residual stress shows a downward trend. The influence of welding sequence on the transverse residual stress is small, but the influence on the longitudinal residual stress is significant. Compared with the whole welding scheme from one end to another end, the residual stress value of T-joint welded by section welding is relatively smaller, and the welding sequence from both ends of the stringer to the middle or from the middle of the stringer to both ends are optimal welding scheme.