Abstract: The carbon atom chemical structure of three Wangqing oil shales was characterized by ¹³C-NMR techniques, and twelve important parameters of the carbon skeleton structure were obtained.Thermogravimetric-Fourier transform infrared spectroscopy (TG-FTIR) tests were used to obtain the formation of light gases during pyrolysis at 50℃/min and the final temperature of 600℃.The FLASHCHAIN model, which was established based on the structure of fuel, was employed to simulate the evolution of pyrolysis products and compared with the experimental tests.The results show that the model has a good simulation below 520℃, some errors occur above 520℃ due to the influence of secondary pyrolysis reactions and decomposition of minerals in the shale.The errors increase gradually with the increasing pyrolysis temperature.