Abstract: Aiming at the spontaneous combustion in widespread closed goaf of Wangtai Mine, the air leakage location in large area goaf was determined by using monitoring technology of SF₆ tracer gas. The control methods, plugging air leakage tunnel, the pressure sharing fire control technology by adjusting the ventilation direction to change the differential pressure and the nitrogen injection and fire prevention measures in goaf, the application of DM-1000 underground mobile membrane nitrogen generator to carry out the sealed nitrogen injection, are used. By adopting a series of comprehensive fire prevention measures, the CO concentration in goaf is greatly reduced and the spontaneous combustion is effectively controlled.