The coal seam of Huoshizui Coal Mine in Shaanxi Province adopts comprehensive mechanized top coal caving mining, and the coal seam has the tendency of spontaneous combustion. ZF8709 working face has a long time to stop mining. In order to avoid spontaneous combustion of residual coal in goaf, the research on fire prevention and extinguishing technology was carried out. The CFZ20 automatic negative pressure sampler was used to analyze the gas concentration in the goaf. The oxygen concentration of 18 % and 8 % was used as the dividing line to determine the distribution range of the heat dissipation zone, the spontaneous combustion zone and the suffocation zone. Pret material is an ideal fire-fighting material with the advantages of high expansion ratio and good diffusion performance. In order to prevent coal seam spontaneous combustion, the fire prevention and extinguishing technology of goaf sealing after full-length frame of working face + preventive grouting at both ends + continuous nitrogen injection is adopted. On-site monitoring showed that the CO concentration was stable below 0.0010 % during the shutdown period, and no signs of ignition were monitored.