In order to overcome the certain shortcomings of traditional methods in studying the pyrolysis process of coal, a sectioning method is proposed in this paper. Taking Xinglongzhuang coal for example, the pyrolysis process is divided into three parts based on the thought of sectioning method and the characteristics of weight loss curves. The interfacial chemical reaction model, the internal diffusion model with the constant volume of resultant and the internal diffusion model with the shrinking volume of resultant are established to fit the experimental data, respectively. The results show that experimental data can be well fitted by the established models. Finally, the corresponding kinetic parameters are calculated for each stage. The sectioning method is successfully applied to describe the pyrolysis process of Xinglongzhuang coal, which provides a theoretical guidance for the simulation and expanded production.