This study investigates the oxidation combustion of bituminous coal in low-oxygen environments using thermogravimetry and differential thermogravimetry (DTG) tests. The research focuses on three coal samples from different regions in China. Key findings include: 1. **Thermal Behavior and Kinetic Properties**: As oxygen concentration decreases, the combined combustion index of the coal samples also decreases during the oxygen-absorption stage. The apparent activation energy of coal increases with its conversion rate (temperature). 2. **Reaction Mechanism Shift**: The reaction mechanism shifts from three-dimensional dissipation mode to two-dimensional as the oxygen concentration decreases. During the pyrolysis combustion stage, the activation energy initially rises and then decreases with increasing conversion (temperature), with a shortened phase of increased activation energy at lower oxygen concentrations. 3. **Kinetic Mechanism Transition**: The kinetic mechanism transitions from stochastic nucleation and growth to one-dimensional phase-boundary mode with decreasing oxygen concentration. These insights enhance the understanding of coal oxidation combustion in low-oxygen environments, contributing to strategies for mitigating coal spontaneous combustion. The study emphasizes the importance of oxygen concentration and heating rate in the thermodynamic behavior of coal combustion under low-oxygen conditions.This study investigates the oxidation combustion of bituminous coal in low-oxygen environments using thermogravimetry and differential thermogravimetry (DTG) tests. The research focuses on three coal samples from different regions in China. Key findings include: 1. **Thermal Behavior and Kinetic Properties**: As oxygen concentration decreases, the combined combustion index of the coal samples also decreases during the oxygen-absorption stage. The apparent activation energy of coal increases with its conversion rate (temperature). 2. **Reaction Mechanism Shift**: The reaction mechanism shifts from three-dimensional dissipation mode to two-dimensional as the oxygen concentration decreases. During the pyrolysis combustion stage, the activation energy initially rises and then decreases with increasing conversion (temperature), with a shortened phase of increased activation energy at lower oxygen concentrations. 3. **Kinetic Mechanism Transition**: The kinetic mechanism transitions from stochastic nucleation and growth to one-dimensional phase-boundary mode with decreasing oxygen concentration. These insights enhance the understanding of coal oxidation combustion in low-oxygen environments, contributing to strategies for mitigating coal spontaneous combustion. The study emphasizes the importance of oxygen concentration and heating rate in the thermodynamic behavior of coal combustion under low-oxygen conditions.