Negative-pressure automatic water-draining device

The invention provides a negative-pressure automatic water-draining device which comprises a gas-water separation chamber, a water-draining chamber and a plugging device, wherein the lateral part of the gas-water separation chamber is provided with a mixture gas inlet, and the top is provided with a gas outlet; the water-draining chamber is arranged at the bottom of the gas-water separation chamber; a baffle plate is arranged between the water-draining chamber and the gas-water separation chamber, and the water-draining chamber and the gas-water separation chamber are communicated by a water inlet arranged on the baffle plate; the lateral part of the water-draining chamber is provided with a depressurizing port and a water-draining port; the plugging device is arranged in the water-draining chamber and arranged on a guide rod in a sliding mode, and the guide rod is fixedly arranged in the water-draining chamber; and the plugging device is used for plugging the water inlet, so that a negative pressure can be kept in the water-draining chamber. The negative-pressure automatic water-draining device provided by the invention overcomes the defects that a large amount of time and labor are consumed in the manual drainage process of the accumulated water seeping into an extraction pipeline and the accumulated water seeping into the extraction pipeline is difficult to drain in time in the prior art, thereby achieving the purpose of the negative-pressure automatic drainage of the accumulated water seeping into the extraction pipeline.