Abstract: The 924 working face of Qidong Mine is covered with 8₂24 gob, with the mining of working face, the connection of upper and lower gobs intensified the residual coal oxidation of gob. During the mining of 924 working face, it was found that there was a high temperature risk area in the overlying 8₂24 gob. In order to eliminate the safety hidden danger, the risk of spontaneous combustion in the upper and lower gobs of 924 working face is analyzed. By adopting comprehensive fire prevention and extinguishing technologies including blocking upper and lower air leakage passage, injecting nitrogen to inert upper and lower gobs and fixed-point pouring into three-phase foam to eliminate high temperature points, in the mining process of 924 working face, the upper corner of 924 working face does not appear CO overrunning phenomenon and the gas indicators of overlying 8₂24 gob remain normal state, which ensures the safe mining of 924 working face.