分析了焦作矿务局九里山矿放顶煤工作面沿底掘进及开采期间各生产工序瓦斯涌出规律． 与顶分层开采对比， 放顶煤开采相对瓦斯涌出量降低， 绝对瓦斯涌出量增加倍数小于产量提高倍数， 各生产工序以放煤时瓦斯涌出量最大； 沿顶掘巷的平均瓦斯涌出量是沿底掘巷的１ ．２５ 倍， 沿底掘进不增加突出危险性 The law of gas emission in each production process during the excavation and mining of the caving face of the caving coal face in Jiu Lishan Mine of Jiaozuo Mining Bureau was analyzed. Compared with the top stratified mining, the relative gas emission of caving coal is reduced, the absolute increase of gas emission is less than the increase of production, and the gas emission is the most during each production process; Emission is along the bottom of the roadway 1. 25 times, digging along the bottom does not increase the prominent danger