Abstract: Compared with traditional fossil fuels, shale has the characteristics of complex mineral components, low organic matter content and uneven distribution. In order to fully exploit and utilize shale, the shale of the coal-bearing formation in the lower Yangtze Wuwei Sag is studied. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric differential scanning calorimetry (TG−DSC) were used to study the mineralogical characteristics and thermal stability. XRD results show that the main minerals of shale in this area are quartz and illite, followed by chlorite, kaolinite, carbonate and feldspar, and there is a superposition of amorphous organic matter in the spectrum. FTIR results show that shale samples from this area are rich in clay minerals and contain small amounts of organic matter. The organic matter is mainly aliphatic hydrocarbon group, but it is not mature. The TG−DSC results show that the pyrolysis zone of organic matter moves to the high temperature zone with the increase of heating rate. Air is more helpful than nitrogen to reduce the ignition point of shale and broaden the pyrolysis zone of organic matter. The characteristic temperature increases with the increase of heating rate, and this trend is more obvious for samples with high organic matter. With the increase of heating rate, shale pyrolysis moves to the high temperature area. Under different heating rates, the pyrolysis index of shale with higher organic matter is better than that of shale with lower organic matter. The pyrolysis index in air atmosphere is higher than that in nitrogen atmosphere. The increase of heating rate is conducive to the release of products. The release characteristic index of shale pyrolysis products in nitrogen atmosphere is higher than that in air atmosphere.