Abstract: With the rapid expansion of the coal chemical industry, groundwater contamination induced by intensive industrial activities in industrial parks has become an increasingly serious environmental concern. However, under the combined influence of multiple pollution sources and seasonal hydrological variations, accurately identifying the origins of groundwater pollution remains challenging. In this study, 20 groundwater samples were collected during both the dry and wet seasons in a coal-to-liquids chemical industrial park. Hydrochemical spatiotemporal characteristics were systematically analyzed, and positive matrix factorization model (PMF) was applied to quantitatively apportion pollution sources. The results indicate that groundwater in the study area is generally neutral to slightly alkaline, dominated by freshwater and hard water types, and that most ion concentrations exceed natural background levels. During the dry season, exceedance rates of Na⁺, SO₄²⁻, and F^- were 25%, 20%, and 15%, respectively, while during the wet season, SO₄²⁻ and F^- exceeded 20% and 10%, respectively. NH₄⁺ exceeded standards only at a few sites during the dry season. High concentrations of Na⁺ and SO₄²⁻ were mainly distributed in the slag storage and production areas, whereas elevated levels of F^-, NH₄⁺, Fe, Mn, Zn, and As were observed across the entire industrial park. PMF model identified five major pollution sources and quantified their respective contribution rates. Fe, Mn, and Zn were mainly derived from coal mineral pyrolysis and coal gangue leaching (26.92%). F^- originated from multiple processes, including dissolution of geological minerals, coal pyrolysis, release of readily soluble fluorine from coal gangue, and leakage of industrial materials (20.07%). As was primarily associated with the dissolution of arsenic-bearing minerals and the leaching of pyrolytic residues (20.01%). Na⁺ and SO₄²⁻ were mainly controlled by desulfurization wastewater, by-product spillage, and salt leaching from solid wastes (18.97%). NH₄⁺ originated from thermal decomposition of organic nitrogen in coal and microbial transformation in slag storage areas (14.03%). The enhanced rainfall recharge during the wet season intensified the leaching and transport of pollutants. Furthermore, it reshaped the contribution pattern of groundwater pollution sources and the composition of dominant controlling factors, resulting in differentiated hydrological responses among various contaminant components. These findings provide a robust scientific basis for the precise identification of multi-source groundwater contamination and for improving source-targeted pollution control strategies in coal chemical industrial parks.