Abstract: In order to control the spontaneous combustion in 2272 goaf of Gongquan Coal Mine and resume the safety production of 2273 working face as soon as possible, liquid CO₂ direct injection and fire-extinguishing technique was adopted, and liquid CO₂ was transported to the vicinity of 2273 working face by using KRM-1200 liquid carbon dioxide fire-extinguishing device. Through high pressure hose connected to the fire prevention drilling, liquid CO₂ was directly injected into spontaneous combustion zone of 2272 goaf. The concentration of CO decreased sharply in 2272 goaf, and the index gases such as C₂H₂ and C₂H₄ disappeared.