Abstract: Addressing the problem that the initial weld entrapped slag rate of the Φ762 mm×30.2 mm X65 SAWH pipe is up to 20%,the causes for occurrence of entrapped slag in weld fusion line of the heavy-wall SAWH pipe,and effect by welding process parameters on weld-entrapped slag occurrence are analyzed. Accordingly,improvement actions are proposed. Owing to repeated tests and setting of the process parameters,the said entrapped slag rate is reduced to be under 5%,and the pipe rework rate is in turn cut down,and thus the productivity is remarkably enhanced.