Based on SYSWELD simulation software, a computational method combining the thermal elastic plastic finite element method(FEM) and the inherent strain method FEM is used to study the influence of the welding process on welding defor-mation of the thin-walled GH3536 tail nozzle assembly. Firstly, the plate docking process test and thermal elastic plastic FEM calculation are carried out to check the welding heat source model, and the average inherent strain value of the joint and the modified thermal expansion coefficient of the material under different welding processes are obtained. Secondly, the finite element model of full-size three-dimensional tail nozzle welding is established. Based on the elastic FEM of the inher-ent strain theory, the influence of welding process parameters and welding constraints on the welding deformation of the tail nozzle assembly was calculated by using the thermal expansion coefficient of the material obtained by plate docking. The results show that when the welding current is 40 A, the minimum inherent strain value of the thin-walled GH3536 plate butt welding joint is 0.00660 mm, and the deformation of the nozzle after welding is also the smallest, which is the recommended optimal welding process. When the weld, air inlet and exhaust port are clamped at the same time, the deformation of the nozzle is the smallest after welding, and the overall deformation is 1.39 mm.