Abstract: In order to study the spontaneous combustion laws of repeated mining and original coal seams in Jingezhuang Mine, using element analysis, infrared spectrum experiment and temperature-programmed experiment, the spontaneous combustion characteristic experiments on the repeated mining and the original coal samples of 1090 and 3320 working faces of Jingezhuang Mine are carried out. The research show that: coal molecular chain is broken up and produces a lot of methyl, methylene because of the cutting or external force of the early mining machine, meanwhile, coal samples are in contact with oxygen in advance and create a lot of hydroxyl groups and new oxygen containing functional groups, leading to the increase of the oxygen-containing functional groups and hydroxyl of repeated coal samples, and the coal spontaneous combustion tendentiousness is strengthened. The macro performance of CO release quantity and O₂ consumption of repeated coal samples is more than that of the original coal samples, and characteristic temperature of repeated mining is also earlier than that of the original coal samples. It is indicated that the oxidation of the repeated coal is stronger and more flammable.