Abstract: Coal seam 22# of Cuncaota Coal Mine is non-sticky coal with lower metamorphism, and the CO production is large under low temperature oxidation condition. Combined with the actual situation of coal seam occurrence in 22301 working face, through laboratory test and analysis, the indicator gas of spontaneous combustion in 22# coal seam is optimized. Based on theoretical calculation, the prediction model of CO concentration in the corner of return air under normal advancing and mining conditions of working face is constructed, the key technical parameters of spontaneous combustion fire in goaf are measured on site, the early warning value of CO concentration in the corner of return air of working face is determined, and the control technology of CO gas overrun in the corner of return air of working face is standardized and improved.