关键词: 地面L型钻孔, 抽采瓦斯, 采空区, 瓦斯浓度

Abstract: in allusion of the problem of the gas controlling which is in the condition of the low content, high flow, high intensity mining of Tashan coal mine . In Datong mining area coal，carboniferous seam gas content is low and coal permeability is poor. Nowadays the methods of the conventional drainage at home and abroad can not solve the problem of the transfinite gas in Tashan coal mine. But using ground "L" type drilling method, we can extract the gas which lies in the high gas concentration area behind the upper corner of the stope face. The gas concentration in upper corner and in the return air lane will reduce significantly .In upper corner of the stope face ，the gas concentration will decrease by a large margin sharply .The gas concentration is only 0.05%. The effect of the gas extraction is obvious. It has reference uses for providing a new way for gas controlling in high-intensity mining fully mechanized caving mining face.