Abstract: Mine gas disaster?is?one of the major?factors?affecting?coal mine safety production,?gas pre-drainage?can effectively?release the gas?potential?in the coal seam,? the?nature of the change of coal itself,?achieve the goal of eliminating coal seam outburst danger area.In order to solve the problem of Da PingMine?Underground gas drainage borehole extraction concentration is low,the effect of non-compliance,?the sealing?quality is poor,this article introduces a new type of gas drainage hole sealing process, namely the coal powder borehole sealing technology pressure grouting hole sealing method, the hole sealing principle, method of sealing hole, hole sealing effect and hole sealing cost and so on are discussed. By polyurethane with Pacific mining active hole sealing process, the effect of hole sealing, sealing hole efficiency, workers labor intensity, etc have improved a lot，In the laboratory and the Da Ping Mine underground borehole, sealing grouting, gained good hole sealing effect, to improve mine gas extraction result provides a theoretical and technical support.