Taking the spent fuel pool of one domestic nuclear power station currently under construction for example,the application of automatic argon tungsten-arc welding process to the stainless steel liner of spent fuel pool has been studied. By verification of type selection,groove design and welding parameters of welding materials,and consideration of actual application condition on site,it shows that the performance of welding joint can meet the requirements of nuclear power design standard,and this technology can effectively improve welding quality and efficiency compared with traditional manual argon arc welding method.