Abstract: Coal spontaneous combustion mechanism is the theoretical basis of prevention and control of coal spontaneous combustion. The existing coal spontaneous combustion mechanism functions have fitted better in the high temperature oxidation stage, but in the low-temperature oxidation stage, the imprecise of the kinetic parameters testing and solving results in poor fitting effect. Micro-calorimeter C80 is used to test thermal properties of low-temperature oxidation of coal samples from room-temperature to 200 ℃ under different heating rates. Based on coal thermal properties, the real-time variation law of kinetics parameters of coal samples is obtained with the reaction process in the process of low-temperature oxidation. The kinetic mechanism function of low-temperature coal oxidation process is also determined, which is one-dimensional diffusion (D1) mechanism function, and whose differential form is f(a)=1/2a.