Underground drill stem vibration damping and pressurizing device

The invention discloses an underground drill stem vibration damping and pressurizing device, which is a complete tool for use in oil and natural gas drilling operation and comprises an upper adapter, a spring, a central shaft, a piston shaft, a locking nut, a water inlet valve, a sealing assembly, a pressurizing cylinder, a pressurizing cylinder centralizing barrel, a pressurizing cylinder outer barrel, a water outlet valve, a high-pressure runner and a lower adapter. During drilling, when generating longitudinal vibration, a drill stem drives the adapters, a spring upper plug connector, the central shaft and the piston shaft to move up and down together relative to the pressurizing cylinder; and drilling fluid is sucked and compressed in the pressurizing cylinder. While transmitting power and circulating the drilling fluid, the device absorbs the energy generated in the vibration of the drill stem and converts the vibrational energy of the drill stem into the pressure of the drillingfluid to pressurize the drilling liquid at the bottom of the well. The device damps the vibration of the drill stem, protects the drill stem, increases the jet pressure of a drill bit nozzle and improves rock breaking efficiency.