<p>In order to study the structural evolution and spontaneous combustion risk of residual coal under low-temperature baking conditions in a coalfield fire zone, a gradient pre-oxidation experiment was used to simulate the thermal disturbance effect. The molecular structure, microcrystalline evolution, pore characteristics, and index gas production of coal under different thermal disturbance intensities were systematically analyzed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis–differential scanning calorimetry (TG–DSC), and temperature programmed experiments. The results show that 200&#xa0;°C is the key oxidation temperature for the change in coal properties. At this temperature, the relative contents of free hydroxyl groups and carbon groups reached the peaks of 9.03% and 12.45%, respectively. Moreover, the aromatic layer spacing (<i>d</i>₀₀₂) is closest to the ideal graphite structure, accompanied by a highly developed pore fracture network. Macroscopically, 200&#xa0;°C oxidized coal showed the lowest ignition temperature (<i>T</i>₅) and a significant spontaneous combustion tendency. The generated CO concentration is 173% higher than that of raw coal. This study clarifies the microscopic and macroscopic characteristics and connections of the secondary spontaneous combustion of oxidized coal in the coalfield fire zone, and provides a theoretical basis for fire warning and efficient recovery of remaining coal resources.</p> Graphic Abstract <p></p>