Abstract: According to +500 m level B₁₊₂ coal seam of south mining area in Wudong Coal Mine, the working face is in a closed state. In order to effectively control the problems, including the spontaneous combustion of residual coal in the caving coal goaf of steeply inclined horizontal section, the mining warehouse resurgence of overlying small kiln and surface leakage, some measures are taken to ensure the safety unsealed of working face, such as the loess backfilling, irrigation and grouting on the ground, moreover, the gel injection, nitrogen injection and other comprehensive fire extinguishing methods underground.