Abstract: Based on the analysis of geological characteristics of the study area, it is considered that the geological conditions of H₂S occurrence are the capping effect of dense surrounding rock on the roof and floor, the water-conducting fractured zone is unable to guide the overlying aquifer, and the low degree of coal metamorphism is not conducive to H₂S adsorption, resulting in maximum H₂S concentration of about 0.001 4% in the main mined coal seam 4 during the construction of Yadian mine at the north of Binchang mining area. Through the analysis of sulfur distribution, sulfate type, groundwater, ground temperature and unsaturated hydrocarbons in the raw coal of No.4 coal seam, it is considered that the formation conditions of H₂S in the study area are as follows: the ground temperature of 30-40℃ was suitable for the reproduction of SRB, sulfate provided the material basis, C₂-C₈ unsaturated hydrocarbon provided the energy and material conditions, weak alkaline ground water provided the living environment and BSR was easy to occur. It is judged that the H₂S gas in the mine is caused by BSR type. By optimizing ventilation, grouting and plugging, strengthening drainage and spraying alkalinity and other measures, the H₂S overrun is effectively prevented, and the health of workers and mine safety are guaranteed.