Fixed-point reaming permeability-increasing and hole-sealing pre-pumping method for first mining layer of coal seam group

The invention relates to a fixed-point reaming permeability-increasing and hole-sealing pre-drainage method for a first mining layer of a coal seam group, and belongs to the field of gas control engineering. Comprising the following steps: performing pore-forming construction and parameter recording in a period of sequentially penetrating through a plurality of coal seams; determining the coal seeing length and the coal hole section length of the first mining key coal seam according to the drilling parameters and an imager; drilling to the coal seeing length of the first mining key coal seam, utilizing water pressure to burst through coal seam cutting teeth of a reamer bit, continuously drilling to achieve reaming and hole digging, and completing reaming and hole digging of the first mining key coal seam; collecting and recording the coal output in the hole; an extraction pipe and a hole sealing device are arranged in the hole; after hole sealing, gas extraction parameters of the first-mining key coal seam ar