Abstract: Taking Ⅱ020802 working face of Wulan Coal Mine as an example, we research the fire prevention technology of easy spontaneous combustion coal seam under the condition of no pillar mining. We obtained coal seam spontaneous combustion characteristic parameters of Ⅱ 020802 working face by experiment, and found the support stress characteristics, fracture development and air leakage path of coal rock mass with no pillar mining on the basis of theoretical analysis. In the process of mining, coal mine, taking the stereoscopic monitoring as the main method and assisting targetedly by plugging, grouting, nitrogen injection as well as the implementation of high-level drilling steam fog inhibitor, uses comprehensive fire prevention measures according to the actual situation to smoothly ensure safety of working face.