Abstract: According to spontaneous combustion abnormal condition occurred in a production downtime of No. 1305 fully- mechanized top coal caving mining face i n Shandong Tangkou Mine, the liquid carbon dioxide was provided to control the spontaneous combustion hidden danger occurred in the production downtime period of the fully- mechanized top coal caving mining face. The study results showed that the liquid carbon dioxide applied to the fire prevention and control could effectively red uce the density of each index gas and temperature, the oxygen volume fraction was reduced from 16. 2% to 8. 2%, the carbon monoxide volume fraction was reduced fr om39 x 10- 6to8 x 10- 6, the temperature was reduced from 29.5 °C to 16.3 °C, the spontaneous combustion hidden danger occurred in the production downtime peri od of the coal mining face could be effectively eliminated and safety during the production downtime period of the coal mining face could be ensured.