Abstract: For the exceptional case that there is residual coal in the upper part of the roof of 12205 working place of Selian No.2 Coal Mine, and based on the conditions of spontaneous combustion of coal, the reasons for spontaneous combustion of the residual coal in goaf during the finished period of 12205 working face were analyzed. According to the actual conditions of the working face and the features of every fire prevention technology, we propose the principle of fire prevention of reducing air leakage and reducing oxygen content in goaf, the measures and technologies for fire prevention during the finish period are built, which includes laying air duct cloth on the roof, building loess isolation wall, grouting high polymer materials, nitrogen injection and other ways. The practice proved that the technologies and measures could effectively ensure the safety mining of 12205 working face of Selian No.2 Coal Mine.