Abstract: The top coal caving mining in the fully mechanized caving face of a mine will leave a large amount of coal in the goaf. When the goaf is taken gas drainage measures，it will lead to the air leakage of the working face into the goaf，resulting in the change of the air flow field in the goaf，thereby increasing the risk of spontaneous combustion in the goaf. In view of this problem，the FLUENT numerical software was used to establish the simulation numerical model of goaf spontaneous combustion danger zone. The suit⁃ able air volume of working face was 1 200 m³/min，the extraction amount was 140 m³/min，and the nitrogen injection amount was 1 000 m³/h. The minimum advancing speed of working face was determined to be 2.05 m/d. According to the field test，the pure volume of extraction is 15 m³/min，the wind discharge is 4 m³/ min，and the maximum value of CO in the deep part of the goaf is 2~23 ppm，which better takes into ac⁃ count the gas and fire control.

Key words: coal mine goaf, spontaneous combustion of residual coal, gas, FLUENT software