The serious rust problem existed in steel coil during SAWH pipe unit production . it analyzed caused reason to steel coil rust , and pointed out that the corrosive coil will greatly affect welded pipe production , it can increase defect rate of gas pocket and break arc , hereinto the gas pocket defect rate is 9 times more than that of new steel coil , and break arc defect rate is 2.4 times of new coil . After comparing several  kinds of blasting methods , the on-line blasting project was put forward aim at rust characteristics of steel coil . Meanwhile , it analyzed existed problems and suggested SAWH pipe manufacturers use shot polishing system.