The utility model discloses a dry liner, including the cylinder jacket body, still include the heat -conducting medium layer, cylinder jacket body outer wall is equipped with a plurality of indentures, the increase heat -conducting medium's that the indenture can be tried one's best adhesive force, heat -conducting medium coating is in heat -conducting medium extrusion layer and on the cylinder jacket body outer wall. The utility model discloses simple structure, heat transmission effect well just use the difficult decline of heat transfer efficiency, excellent in use effect through for a long time.