Fuel assembly is the core elements of chain reaction in nuclear power systems. Its structural stability and reliability are critical to the safety of nuclear power operation. Nuclear power plant has high requirements for the welding performance and corrosion resistance of nuclear austenite stainless steel,which is the main component of the nuclear fuel skeleton. At present,most nuclear austenite stainless steels for reactor core parts of nuclear power plant rely on import. This is not good for national nuclear safety. From the angle of the welding performance of domestic nuclear austenite stainless steel for reactor core part,Firstly,three modification experiments are carried out on the trial-produced domestic materials,and the idea of improving welding performance is obtained. Then,for insufficient welding performance of domestic materials,a special welding technology suitable for domestic materials is developed.The new technology utilizes the thermal stress produced by the special geometric structure of weld heat affected zone to restrain the movement of metal in molten pool,thus improving the welding performance of domestic materials. This developed welding technology has passed all kinds of technical evaluation and has been successfully applied to the localization of nuclear fuel assembly manufacturing in the HPR1000. The research results are greatly significant for improving the welding performance and quality of domestic nuclear fuel assembly parts.