Shale gas underground drainage gas recovery device

The invention discloses a shale gas underground drainage gas recovery device which structurally comprises a fixing seat, an oil pipe, a main body, a drainage pipe, a gas guide pipe and a positioning frame, the oil pipe is arranged on the end face of the fixing seat, the main body is connected to the bottom end face of the oil pipe, the drainage pipe is arranged at the top of the side end of the oil pipe pair, and the gas guide pipe is connected to the side end face of the oil pipe. The main body comprises an oil passing groove, a plunger device and an air guiding device, the oil passing groove is formed in the inner end face of the oil pipe, the plunger device is arranged in the oil passing groove and movably matched with the oil passing groove, and the air guiding device is arranged on the bottom end face of the oil passing groove. The end face of the lifting device is supported through the buffer spring, so that the end face of the lifting device can be impacted to extrude the buffer spring when the plunger