To explore the main influencing factors of atomic ratios (O/C, N/C, and H/C) as well as microcrystalline structures (d₀₀₂, L_a, L_c, and M_c) on thermal properties (specific heat capacity, thermal conductivity, and thermal diffusivity) at certain temperatures within 30.0–300.0 °C, three coal samples were collected from coalmines of Dafosi, Yangjiaping, and Hujiahe in Binchang coalfield, Shaanxi Province, PR China. Thermal properties of coal samples were determined by laser-flash apparatus in nitrogen atmosphere. After temperature treated at 30.0, 60.0, 90.0, …, 300.0 °C in nitrogen atmosphere, the atomic ratios and microcrystalline structures of samples were measured by proximate analyser and X-ray diffractometer. The results indicated that with an increment in the temperature, the value of H/C for three coal samples diminished slightly and then promptly, whereas O/C diminished slightly and then increased before 120.0 °C, as well as finally enhanced, and the N/C no obvious change. Concurrently, the microcrystalline structure of coal samples became more orderly and complete. Furthermore, the TD decreased with temperature, the SHC and TC showed an opposite trend with TD. Based upon the method of grey correlation analysis, the major influencing factor of atomic ratios and microcrystalline structures on thermal properties were approached. The results provided insights into the physicochemical properties of the coal of interest for predicting the progress on coal spontaneous combustion.