Abstract: With the first grid connection of Hualong No.1, the welding engineering quantity of small-size pipes De≤φ273mm in each nuclear power project is large and the welding cost is high, and the traditional welding method can no longer meet the current status quo of nuclear power construction and installation. Taking the open full-position automatic welding equipment as the starting point, this paper generally introduces the demand for automatic welding equipment for nuclear power in China, systematically expounds the composition of the equipment and its unique partition welding function, and introduces the welding process test verification results and field application, which provides a reference for the subsequent development and promotion of new products.