Abstract: According to the characteristics of coal spontaneous fire in goaf of caving fully mechanized face, such as wide high temperature range and hidden of high temperature point, based on the requirements of coal spontaneous fire, the compound fire prevention technology of multiple oxygen insulation and three-dimensional cooling is put forward, namely in three aspects of reducing air leakage of goaf, reducing the coal surface in contact with air and preventing air into coal porosity to reduce exposure of coal and oxygen, while through embedded piping in the corner, fire prevention borehole before frame and high level borehole , three-phrase foam is injected into goaf to inhibit the oxidation of coal, thus hidden trouble of coal spontaneous fire is achieved to control . This technology was applied at 1303 working face in Guojiahe coal mine, after the implementation the concentration of CO decreased from 540 ppm to 150 ppm, hidden trouble of coal spontaneous fire in goaf was controlled effectively.

Key words: fully mechanized top coal caving, multiple oxygen insulation, three-dimensional cooling, fire preventing and extinguishing