Abstract: CO gas, as a marker gas in the whole process of coal spontaneous combustion, plays a very important role in the prediction of coal spontaneous combustion. However, a large amount of CO gas can be generated under normal conditions of low-metamorphic coal, which interferes with the prediction of coal spontaneous combustion in low-metamorphic coal seam mining area. Coal samples were collected from five typical mines in Gushan Mine in Pingzhuang, Bulianta Coal Mine in Shendong, Daliuta Coal Mine in Shenmu Mining Area in Shaanxi, Zaoquan Mine in Lingwu Mining Area in Ningxia, and No.1 Mine in Dananhu Mine in Dananhu Mining area in Xinjiang. After oxygen isolation crushing treatment, the CO generation law of coal samples in 5 mining areas during oxygen isolation heating process was studied by using oxygen isolation program heating and Fourier optical interference experiment, and the types of active functional groups on coal molecules with or without oxygen separation heating were analyzed. It was believed that carbonyl (C=O), carboxyl (-COOh), ether (-O-CH3) and other oxygen-containing groups on coal molecules were directly related to the generation of CO gases in low-metamorphism coal at room temperature.