Regional gas underground high-pressure jet hole digging, pressure relief and outburst prevention method

The invention discloses a regional gas underground high-pressure jet hole digging, pressure relief and outburst prevention method, which comprises the following steps of: arranging a plurality of drilling fields (3) in a bottom board rock gangway (2) of a coal bed (1), and arranging one or more drilling hole positions; after a drilled hole (4) reaches the design depth of the coal bed (1), withdrawing drilling, and putting a jet device, a filter device and a connected drill rod into the drilled hole (4); starting a high-pressure water pump, rotationally cutting the hole wall of the drilled hole (4) in the coal bed (1) by the jet device, performing radial continuous hole expanding and digging on the drilled hole (4) when the drill rod moves along the axial direction of the drilled hole (4) so as to form a pressure relief space, and collecting coal dust carried out by jet water flow; after the hole is dug to a certain depth, adjusting the position of the jet device by changing the numberof the drill rod to conti