In this study, we performed a comprehensive analysis of the molecular structural characteristics of low-rank coal and predicted its chemical properties. Using quantum chemistry and wave function analysis, we extensively discussed electrostatic potential surfaces, spectral characteristics, electronic structure, and orbital composition of coal. Our findings reveal that regions exhibiting negative electrostatic potential display increased reactivity during reactions. Oxygen-containing groups in coal molecules exhibit strong hydrophilicity upon interaction with water, primarily through medium-strength and weak hydrogen bonds. Hydrophobic sites are predominantly located near the aliphatic side chains and aromatic core groups of the coal molecules. Additionally, oxygen and carbon atom orbitals dominate regions of lower energy density, correlating with volatile substances that undergo initial decomposition during coal heating. These results provide fundamental insights into the physical and chemical properties of low-rank coal from a molecular perspective.