Abstract: In the preparation stage of withdrawing, 215021 full-mechanized caving face in Wangwa No.2 Mine appears spontaneous combustion in inlet side of goaf, and the CO gas concentration is overrun, which affects the safety withdrawing of working face support. Based on the actual situation and coal seam occurrence conditions, we analyze the overrun reasons of CO gas concentration and develop a governance program. Using the fire fighting technology of playing high drilling filled with yellow mud and polymer colloid, combined with measures of reducing the amount of wind, sealing the top and bottom, the CO gas concentration returns to normal at working face. The CO gas concentration in return current falls down to 11×10^-6 from the highest 77×10^-6, and remains under 24×10^-6 stably, which controls the fire effectively and ensures the safety withdrawing of the working surface support.