Abstract: The gas occurrence mechanism of deep coal seam is an important theoretical basis to guide the safe and efficient mining of deep coal and gas resources. Compared with the shallow coal seam, the occurrence environment of the deep coal seam has the characteristics of high stress, high temperature, high gas pressure and low permeability, which determines the unique characteristics of the deep gas occurrence and the technical problems faced by the deep resource output. We systematically reviewed the influence of stress, temperature, pressure and permeability on the gas occurrence laws of deep coal seam, pointed out the shortcomings of single physical field influence research, and made clear that the multi-field coupling environment is the objective condition for the study of gas mechanism of deep coal seam, and pointed out the direction for the study of gas occurrence mechanism of deep coal seam.