Air pressure drainage device for landfill gas collecting well

The utility model relates to an air pressure drainage device for infiltration liquid of a landfill gas collecting well. The air pressure drainage device for the landfill gas collecting well is connected with an air compressor through an air feed branch pipe; the air feed branch pipe is communicated with a high pressure air pipe in the landfill gas collecting well through a control valve arranged on a wellhead flange; a drain pipe is arranged in the collecting well; the lower end of the drain pipe is arranged at the bottom of the collecting well; the upper end of the drain pipe is led out of the well from the wellhead flange of the collecting well; and the high pressure air pipe is connected into the drain pipe from the bottom of the drain pipe. In the utility model, high pressure air is utilized to blow the infiltration liquid in the collecting well into water foam to drain the infiltration liquid, so that not only is the explosion potential safety hazard generated when a submersible pump is adopted to drain