In order to avoid spontaneous combustion of coal, reduce cost and improve the effect of fire prevention and extinction, this essay brings about the technology and related device to prevent and control the spontaneous combustion of coal based on the properties of fire prevention and extinction of the liquid CO2 toward fire area, such as: asphyxiation oxygen, cooling down and inerting. The technical difficulties such as the safety packing, transportation and perfusion to the fire area underground of liquid CO2 are solved. The liquid CO2 is transported safely to the fire area underground and are infused to fire area in the form of liquid. The on site operation and test proved that the fire-fighting technology and device has the following advantages: high speed, simple operation, adjusted continuously, stable operation, and significant and reliable fire prevention effect. It accords with the actual application and has great practical value.