Used in hydraulic tunnel drilling rig chuck rubber cylinder, rubber cylinder outer diameter of the central support ring and two sections of the pressure plate lock. So that the two sections of the outer diameter of the compression of the formation of a sealed state, barrel external oil pressure after pressurization of radial movement, relying on the reduction of the inner diameter of the enlargement of the push kava locking or loosening of the drilling rod work, Yaxins research of new materials can effectively reduce the gap between the kava on the rubber barrel of the shear (reduce the phenomenon of nibbling), so that the rubber barrel service life is greatly enhanced.