Submerged arc welding is still the most commonly used welding method in industrial production. It is suitable for the welding of larger, thicker and longer straight lines and larger diameter annular welds. Widely used in chemical containers, boilers, shipbuilding, bridges and other metal structures. This method also has deficiencies, such as less manual welding flexibility, generally only suitable for horizontal or inclining welds; workpiece edge preparation and assembly quality requirements, time-consuming; due to submerged arc operation, do not see To the weld pool and weld formation process, therefore, must strictly control the welding specification.