Abstract: To understand the characteristics of coal low-temperature oxidation and its physical process in more detail, temperature-programmed experiments are used to study the evolution of key parameters of the low-temperature oxidation process of different coal sample sizes. The numerical simulation method is used to further explain the detailed characteristics of the multi-physical field evolution of the coal low-temperature oxidation process. The correctness of the numerical simulation was verified based on the experimental results. Based on the combination of experiment and numerical simulation, the characteristics of temperature, mass fractions of reactants and products, and fluid flow of the coal samples in the temperature-programmed experimental chamber were explored. The result shows that the numerical simulation can well characterize the low-temperature oxidation process of coal, and show the change characteristics of the time series of various physical fields in detail. According to the gas emission and oxygen consumption of coal oxidation process, low-temperature coal oxidation can be divided into two stages, with 70 ℃ as the critical value. With the development of low-temperature coal oxidation, the frontier of coal oxidation reaction is moving to the region of high oxygen volume fraction.