Abstract: In order to improve the fire control effect of goaf in fully mechanized mining face, taking the 2135 working face of Jiaojiazhai mine as the research object, aiming at the phenomenon of large air leakage in the goaf and easy spontaneous combustion of residual coal under the "U" ventilation mode, the air leakage law of the goaf and the change law of temperature and gas concentration were analyzed, and the distribution of the "three zones" of natural ignition in the goaf was determined. The comprehensive fire prevention and extinguishing technical measures such as the minimum propulsion speed of the working face are designed to effectively suppress the threat of spontaneous combustion of residual coal in the goaf, realize the accurate management of the spontaneous combustion fire of the residual coal in the goaf, and ensure the safe mining of the fully mechanized mining face.