Abstract: Arc magnetic deviation blowing deflection is often encountered during pipeline welding of space vehicle. Due to the influence of parts material, environment and equipment, it is difficult to determine the cause of arc magnetic deviation blowing, and magnetic deviation blowing will lead to the welding position deviation, resulting in defects such as edge bite, incomplete welding, incomplete fusion, etc. In serious cases, welding will not be able to be applied, which brings trouble to the pipeline weld forming. Therefore, the mechanism of arc magnetic deviation blowing in the welding process of magnetic parts of carrier is analyzed, and the methods to resist arc magnetic deviation blowing are summarized for the welding of magnetic parts in stock.