瓦斯是一种以甲烷为主，多成分的混合气体，其成分CH_4约占63.1～99.22％，N占0.05～35.96％，CO_2占0.06～14.76％。甲烷为无色、无味、无嗅、无毒的气体，化学性稳定，比重比空气轻，当矿井瓦斯集中的地段，随着瓦斯浓度的增加，易使人窒息，遇火燃烧易发生瓦斯爆炸。因此，瓦斯是危害安全生产和工人生命的有害气体。近年来，世界上很多国家普遍重视了瓦斯的抽放和利用。所以，在煤田地质勘探过程中，查明煤层内的瓦斯成分和含量是一项必不可少的工作程序。 Methane is a methane-based, multi-component gas mixture with CH_4 accounting for 63.1-99.22%, N accounting for 0.05-35.96% and CO_2 accounting for 0.06-14.76%. Methane is colorless, tasteless, odorless, non-toxic gas, chemical stability, the proportion of lighter than the air, when the mine gas concentration of lots, with the gas concentration increases, easy to make people suffocate in case of fire prone to gas explosion . Therefore, gas is a harmful gas that endangers production safety and workers’ lives. In recent years, many countries in the world generally pay attention to the gas drainage and utilization. Therefore, in the process of geological exploration in coalfields, it is an indispensable working procedure to identify the gas composition and content in the coal seam.