One side welding both sides forming technology of butt welding in the overhead position with shielded metal arc welding（SMAW） is summarized. The preparation before welding,selection of electrode,the operating points during the welding of backing layer,filling layer and covering layer are also introduced in detail, so as to control the appearance of weld,improve the welding quality,and provide reference for the follow-up production work and the training of backup technical personnel.