In No.2 coal seam mining of Yangquan Group Dengmaotong Coal Industry Corporation, effect, security and cost of two gas drainage methods were compared comprehensively. Large diameter drilling drainage was used to shorten drainage gap, every 20m in pillar bewtten adjacent spare face intake airflow roadway and stope face return airway were set a gas drainage hole with 400mm diameter to replace roadway construction and avoid dead zone of gas drainage, which improved corner transfinite gas in working face and ensured safety production.