To enhance pressure relief and permeability in deep, high-gas coal seams, this paper proposes a surface well cavity creation and pressure relief permeability enhancement technique. A multi-field coupling model of gas migration in the reinforced coal body of the cavity creation area was constructed, analyzing the influence of different parameters on the area of the damaged coal body, permeability, and gas pressure. Simulation based on the coal excavation and cavity creation at the Zhangji Mine A group site analyzed the pressure relief and permeability enhancement effects under different initial permeability and extraction time conditions. The study indicates that reducing borehole spacing promotes connectivity in the damaged area, but excessively small spacing is detrimental to permeability improvement. Increasing borehole size significantly enlarges the damaged area and permeability. The smaller the cohesion of the coal body, the more notable the permeability enhancement effect. With an increase in the internal friction angle, both the damaged area and permeability decrease. Additionally, low initial permeability results in a reduced effective extraction radius. Investigations of underground gas parameters show that after implementing the surface drilling large-diameter coal excavation and cavity creation process, gas pressure and content significantly decrease, the permeability coefficient increases by approximately tenfold, effectively improving gas extraction efficiency.