An energy barrier mechanism exists in the hydrocarbon generation of vitrinite. Traditional coal geochemistry is unable to explain the mechanism of the macromolecular structure evolution in the process of hydrocarbon generation. This paper studies the hydrocarbon generation characteristics by thermal simulation experiments to obtain the control mechanism of the vitrinite macromolecular structure evolution control on hydrocarbon generation. The vitrinite structure characteristics were studied by Fourier transform infrared spectroscopy (FTIR) and carbon-13 nuclear magnetic resonance (C-13 NMR), and the structural parameters of vitrinite were calculated. On the basis of building the model of the macromolecular structure in a vitrinte sample, the coupling mechanism between hydrocarbon generation and the evolution of the vitrinite structure was determined through quantum chemistry. These results are important and practical for the coalification theory and coalbed methane (CBM), shale gas, and other unconventional gases. The results showed that the hydrocarbon production rate increased along with increasing maturity. Gaseous hydrocarbon consists of methane and heavy hydrocarbon alkanes and alkenes. The C2-5/C1-5 ratio decreases linearly with increasing maturity. The intensity of the vitrinite functional group absorption peak decreases. Aliphatic hydrocarbons have an absorption peak before 430 degrees C, which then declines to periodic variation characteristics. The intensity of the absorption peak because of the C=O moiety of aromatic hydrocarbons (1600 cm(-1)) decreases. The response of the intensity of substituted aromatic hydrocarbons is weak. A polyester reaction occurs at 450 degrees C. The aromatic carbon rate change is divided into three stages. The average molecular potential energy decreases with the pyrolysis process. Vitrinite removed the methyl macromolecular structure first and then the aliphatic hydrocarbons, aliphatic chain rings, and other bonds.