To enhance flotation efficiency of scarce coking coal slimes, this study investigated n-hexane and cyclohexane as flotation reagents, systematically examining how aliphatic chain versus cyclic molecular structures influence coal slime beneficiation performance using 1/3 coking coal from Xinwen Coal Preparation Plant. Integrated methodologies including flotation tests, contact angle measurements, density functional theory (DFT) computations, and molecular dynamics (MD) simulations elucidated structure-performance relationships at macroscopic and microscopic scales. Results demonstrate n-hexane's superior flotation efficacy compared to cyclohexane: at 2000 g/t collector dosage, n-hexane achieved 68.93% combustible recovery versus 64.79% for cyclohexane. Contact angle analysis revealed coal particles treated with n-hexane exhibited 178° hydrophobicity, significantly higher than the 152° observed with cyclohexane. DFT calculations indicated n-hexane's higher molecular polarity index (MPI is 2.85 kcal/mol) versus cyclohexane (2.45 kcal/mol), signifying stronger adsorption affinity on coal surfaces. MD simulations further confirmed n-hexane's enhanced spreading behavior and reduced molecular mobility on coal interfaces relative to cyclohexane. This work establishes that the collector with long chain structure is more advantageous in the process of coal slurry flotation, which provides a theoretical basis for the molecular design of high-performance coal slurry flotation capture agent.