Gas extraction secondary high-pressure slip-casting hole-sealing apparatus and its hole-sealing method

A secondary high-press pulp injection and hole sealing device for collecting gas comprises collection pipes, bags and a secondary pulp inflow device, wherein collection pipes are connected with two sides of the secondary pulp inflow device; plugs are sleeved on the collection pipes; the bags are located between each plug and the secondary pulp inflow device; three pulp inflow holes having unidirectional valves are arranged on the secondary pulp inflow device; the pulp inflow holes on the two sides communicate with the bags on the same side; and the pulp inflow hole in the middle spatially communicates with the bags. A method of using the device for pulp injection and hole sealing comprises the following steps of: inserting a pulp injection plug in the secondary pulp injection device and performing the low-pressure pulp injection to the pulp inflow holes that communicate with the bags; and after the injected pulp is solidified, performing the high-pressure pulp injection to the pulp inflow hole in the middle of the secondary pulp inflow device by using the pulp injection plug. The invention adopts the pulp injection materials to inject the pulp to the drill hole wall so as to seal the drill hole wall and the peripheral deflated passages thereof, and basically eliminates the drill deflated cracks through the primary low-pressure pulp injection and the secondary high-pressure pulp injection close to the ground stress.