Abstract: Considering the problems of difficult sealing methods, unreasonable sealing length of integration borehole for hydraulic fracturing and gas drainage, based on previous gas extraction sealing method of sealing section between the two ends, a modified sealing method was used, and capsule mechanical model was established to determine reasonable sealing length. According to reasonable maximal hydraulic fracturing pressure of Shoushan No.1 Coal Mine F_15-17 coal seam, the reasonable sealing length is 10 m. Layer-through boreholes in different sealing lengths were arranged to compare the effects. Result shows that 10 m sealing length can meet requirements in hydraulic fracturing and gas extraction when maximal hydraulic fracturing pressure is 25 MPa.