Abstract: EGF seepage increasing fluid is used to increase the permeability of coal mine gas predrainage boreholes，thereby improving the extraction effect. Through the test and analysis of 22311 working face in Yonglong mining area，after using EGF seepage increasing fluid，the single hole extraction concentration of directional drilling can be increased by about 10 times，the average increase is about 3 times， and the gas extraction flow is increased by nearly 2 times. The seepage increasing fluid achieves the purpose of improving the extraction rate of the working face and shortening the pre-extraction time，and has the characteristics of high efficiency and green.

Key words: EGF seepage increasing fluid, gas pre-drainage, extra-thick coal seam