Abstract: The magnetic arc blow phenomenon appears at the groove during high-pressure steam pipeline welding process, and it is difficult to form molten pool, the forming effect can not meet the welding requirements. The causes of magnetic field formed in the pipelines was analyzed. According to actual operation conditions, the welding method of winding coil and bridging magnetization was adopted to effectively solve the welding problem that argon arc welding can not be carried out under the interference of strong magnetic field. The results show that although the winding coil method can effectively reduce the strong magnetic interference of the pipeline, it is hard to completely eliminate the magnetism. On this basis, using the bridge method at the groove finally realizes the argon arc welding for the pipeline with strong magnetic field, and effectively guarantees the welding quality. It provides references for similar maintenance problems of high-pressure steam pipelines in the future.