Abstract: In chengzhuang coal mine goaf of fully mechanized working face the problem of large gas emission, km deep hole drilling rig technology and form a complete set of equipment, application of goaf roof is test long high directional drilling gas extraction technology; By studying goaf "three zones" gas, distribution scope and design of goaf roof long high directional borehole layout parameters. Test results show that super long borehole directional high gas extraction technology has low drilling construction quantities, location is good, stable extraction, extraction rate increase, the advantages of significant extraction results have been achieved.