Tunnel engineering precipitation pressure drainage device

The utility model relates to a tunnel engineering precipitation pressure drainage device which comprises a water tank, a pressure ball, an elastic force application assembly, a drainage water inlet pipe, a drainage water outlet pipe, a piezometer, a first pipe valve and a second pipe valve. The top of the water tank is open, a water inlet is formed in the bottom, and a water outlet is formed in the middle. The lower portion of the water tank is matched with the pressure ball in shape. The pressure ball is attached to the inner wall of the water tank and blocks the water inlet. The elastic force application assembly comprises a telescopic sleeve, a spring, a sliding disc, a push-pull rod and a nut. The diversion water inlet pipe is a bent pipe comprising three right-angle bends, the outlet is upward and is connected with the water inlet of the water tank, and the inlet is communicated with a target water source; the piezometer and the first valve are both arranged on the drainage water inlet pipe; the inlet of