Jizhong Energy Jingxing Mining Group Zhengzhu Mine is located in the east wing of Qinshui Coalfield Zuoquan Mine area， No. 15 coal seam in Zhengzhu Mine was high-gas easily spontaneous . Based on exploitation characteristics of spontaneous combustion thick coal seam sub-level caving of Zhengzhu Mine and study on fire-fighting technologies of characteristics of No. 15 coal seam’s spontaneous combustion， spontaneous combustion forecast indexes of gas， goaf "three zones" of spontaneous combustion， fire-prevention technology by infusing nitrogen and fire area precise positioning technology (isotopic radon measurement method)， the system of early prediction of spontaneous combustion and comprehensive fire-fighting technology of coal seam were built preliminarily in ZhengZhu Mine. It was not only significant to reduce the rate of mine spontaneous combustion fire accidents， improve the level of mine spontaneous combustion fire prevention， but also be conductive to cost decreasing and benefit increasing and maintain the safety work stability.