Abstract: In order to determine the optimum hole spacing for gas extraction borehole, a gas-solid coupling mathematical model considering the evolution of coal permeability, solid mechanics and gas diffusion-seepage was established based on the assumption of pore-fracture dual media.Taking the N2206 working face of Yuwu Coal Mine in Shanxi Province as the research object, the numerical simulation study of gas extraction in single borehole and multi-borehole was carried out, and it was found that the effective extraction radius and the extraction time changed as a power exponential function, and the average error between the numerical simulation results and the field test results was 4.69%.Based on the model validation, the influence of hole spacing on the superposition effect was analysed according to the principle of superposition effect in multi-well gas extraction, and a mathematical model of hole spacing in multi-well gas extraction was established based on effective extraction radius and the influence radius of a single well.It was found that the optimal hole spacing of N2206 working face was 9.2 m.Field testing has confirmed the accuracy of the formula correlating hole spacing with the effective extraction radius and influence radius of a single hole.