Abstract: The hydraulic fracturing drilling in the coal mine is mainly applied to increase the permeability of the coal seam, and the sealing quality is one of the key factors that affect the fracturing. In order to improve the quality of borehole sealing, a new sealing method of borehole cementing is proposed. A suit of sealing technology with packer is developed based on the existing sealing technology, which meets the technical requirements of hydraulic fracturing in underground coal mine. The results show that there are no leakage of mud at the 30 MPa fracturing pressure of the 97 hydraulic fracturing boreholes in Huainan Mining Industry Company. After fracturing, the permeability coefficient of coal seam is 5 times more than that of the original state, the drainage quantity of single hole and the unit is all 2 times more than that of the original state.