Method for extracting coal seam gas through cooperation of large-diameter drill hole and layer-by-layer stripping technology

The invention relates to a method for extracting coal seam gas through cooperation of a large-diameter drill hole and a layer-by-layer stripping process, and belongs to the field of coal mine safety. The method comprises the steps that S1, a large-diameter drill hole is constructed in a transportation crossheading of a stope face, and a center drill hole is constructed; s2, a drilling machine is started to enable a driving rod to rotate, a swing gear is driven to rotate, the driving rod swings up and down, and a longitudinal fan-shaped slot is formed; s3, the device is horizontally placed, and transverse fan-shaped slots are constructed; s4, the gas extraction pipe is put into the large-diameter drill hole, the large-diameter drill hole is plugged, and after plugging operation of the large-diameter drill hole is completed, gas extraction is started; and S5, supplementing gas extraction drill holes are constructed in the left side and the right side of the large-diameter drill hole every certain distance, so t