Abstract: Aiming at the oxide and welding slag polishing problems in the heat-affected zone of inner wall of steel welded elbows, the mixed abrasive of ceramic carrier, silicon carbide steel sand and water in a certain proportion was put into welded pipe, and it was fixed on the spring vibration grinding groove. Using the three-dimensional vibration effect, the grinder drives the abrasive to vibrate at high speed in the pipe, and the abrasives can continuously cut the inner wall of the pipe, so as to realize the polishing of welding spot on the inner wall of pipe. It is found that when the mixing ratio of ceramic carrier,silicon carbide steel sand and water is 5 : 1 : 1, the loading volume is 80% of the volume of the welded pipe, the rotating speed of the vibration grinder is 1000 r/min, and the polishing time is 10 min, the welding spots on the inner wall of elbow in φ76-2 mm pipe are effectively removed, and the surface polishing quality can reach level 2. At the same time, the vibration polishing can effectively eliminate the residual stress of the pipe assembly weldment, and the stress relief rate can reach maximum of 50%, which is higher than the single processing effect of vibration aging or impact aging.