Abstract: The present work was carried out to obtain the welding residual stress distribution of double-side single-pass welding of T-joints. The small hole method was used to measure the residual stress at the weld of test pieces. At the same time, a three-dimensional welding finite element model of T-joint was established by using ANSYS software. Based on the indirect coupling method, numerical simulation and prediction of the welding process were carried out, and the welding residual stress distribution was obtained. The influence of different welding sequences on residual stress distribution and welding deformation was also studied. The results show that the welding residual stress distribution obtained by numerical simulation is in good agreement with the experimental results. Compared with single-pass welding in the opposite directions, single-pass welding in the same direction will reduce the residual stress along the weld direction, with smaller deformation and better perpendicularity. The research results provide a reference for the welding process optimization of double-side single-pass welding of T-joints.