Abstract: The temperature field and residual stress field of Ti₂AlNb titanium alloy electron beam welding joint were studied by using Gaussian surface and rotary body composite heat source based on finite element software. The results show that the welding joint is well formed when the electronic beam current is 10 mA and the welding speed is 360 mm/min. It is preferred to use a big electron beam current to form welded seam with large weld width.The central area of the weld suffers complex stresses in three directions, and the residual stress is mainly longitudinal tensile stress, which is concentrated within 3.5 mm from the weldline.The maximum equivalent stress after welding is 635 MPa, which is less than the yield strength of the material, so the structure is safe.