Abstract: Aiming at the TIG welding problem between flame tube fairing and eight supports of an aero-engine,numerical simulation tests were carried out based on the thermo-elastic-plastic finite element theory, and the relationship between the temperature and the materials properties were also considered. Firstly, the accuracy of the numerical simulation method was verified by the lap welding experiment. Then, the deformation and residual stress of the flame tube fairing under different welding cases were obtained by using numerical simulation method. The results indicate that the maximum value of deformation can be slightly decreased by adopting interval welding or symmetrical welding method. Serious deformation is obtained by using the welding direction from top to bottom for the two welds of the support. The magnitude and distribution of residual stress are barely influenced by changing the welding sequence and direction. The residual stress along axial direction of the fairing is tensile stress, and the residual stress of rear welding joint of the supperts is larger than that of first welding joint. Comprehensively considering the magnitude and distribution of deformation and residual stress, interval welding and welding direction from bottom to top is recommended.