We combine the advantages of automatic control and argon arc welding to achieve efficient and high-quality pipeline welding. Numerical control system is used to control and monitor the welding process. It can precisely control the welding arc length and moving speed during the welding process to achieve stable welding quality and consistency. The welding defects such as pores, inclusions and oxidation are reduced during the welding process. Greatly improve the tightness and strength of welded joints, to ensure the reliability and durability of the pipeline.