Abstract: For the situation that multiple air leakage channels existed in the overlying strata and air leakage in the gob is serious, during the mining process of lower leaf sub-level caving working face, which would cause spontaneous combustion in goaf.Aim to prevent the potential self-heating in gob of upper layer and the working face of lower layer, the comprehensive measures such as pre-grouting, nitrogen injection, water injection, blocking the air leakage channel in underground and surface, ventilation system adjustment, and the application of monitoring and control system, was carried out in the first working face in the lower layer.All these measures could ensure the mining safety and prevent the spontaneous combustion in gob.The mining safety of working face in the lower layer was guaranteed.