Abstract: This paper mainly aims at the visible and fluorescent defects in the welding process of GH5188 alloy parts and GH3536 alloy parts in the flame tube manufacturing process. Through the electron beam welding process of heterogeneous alloy plate test pieces and simulation pieces, the defect types and causes are clarified, and finally the defect free welds are obtained. The main welding defects are black concave spots at the weld, which are analyzed by energy spectrum as oxides of Al and La. By strictly controlling the whole welding process of the simulated part, the electron beam weld without defects was obtained. In addition, the welding morphology and microstructure characteristics of GH5188 alloy and GH3536 alloy welded by electron beam were observed, and the mechanical properties of welded specimens were tested.