According to the welding of the main circuit pipelines of nuclear power plants such as M310,CPR1000 and AP1000 in China,automatic welding technology has been successively implemented,which has significant effects in improving construction efficiency and quality. Combined with the characteristics of Russian VVER stacked main pipeline composite steel material,the present situation of automatic welding of main pipeline of nuclear island in China is fully discussed. It is of great significance to develop the construction technology of composite steel automatic welding for main pipeline with Chinese characteristics, utilize foreign resources and promote the feasibility study of international cooperation.