Abstract: For the features of low-rank coal, good permeability and high gas in the coal seam of Hunchun Coal Mine, we carry out industrial tests of hydraulic fracturing,compare and analyze the gas extraction concentration inside and outside the high drilling fracturing area, extraction parameters before and after fracturing of mining-coal bed pre-drainage holes, gas emission at working face and dust fall effect. The results show that gas extraction concentration of high level borehole inside fracturing area averagely increased by 2.65 times than that outside fracturing zone; the gas extraction concentration of mining-bed pre-drainage borehole after fracturing averagely increased by 1.83 times, flow increased by 39 times averagely, than that before fracturing. The gas emission at working face reduced to 9.82 m³ / t of phase 1 fracturing area and 7.51 m³ / t of phase 2 fracturing area respectively from 23 m³ / t outside the fracturing area. Fracturing effect radius is 20 m to 34 m, the interval of mining-coal bed coal seam pre-drainage borehole also increased greatly.