Abstract: Following the problems concerning the steel pusher of the Φ100mm piercer located at Tianjin Municipal Seamless Steel Tube Plant, such as hitting against the cylinder back cap and loose linking between the rod and piston, countermeasures were taken to solve the said troubles so as to maintain normal operation of the tube mill. The measures include increasing the buffering stroke, adoption of an air-cushion damping device, controlling of the piston returning speed as well as strenghtening the linkage between piston and the rod.