“FaceFace”high differential rotation speed wear equipment was designed to investigate the impact wear properties between piston ring and the joints on extralongstraight steam engine cylinder liners.By simulating the sliding speed,contact pressure and status between piston ring and cylinder,the wear of piston rings and cylinder liners was measured and their surface morphology was observed.Conclusions are as follows,“FaceFace” high differential rotation speed wear equipment can be used to investigate the impact wear properties between piston ring and the joints on extralongstraight steam engine cylinder liners;the chamfer on the joints between cylinder liners will increase the wear of cylinder liner,especially the wear of piston ring;the wear on the facepiston ring position of cylinder liner is serious,while it is mild on other positions.