Abstract: Polycyclic aromatic hydrocarbons (PAHs) are hazardous contaminants generated during the thermal processing of edible oils and have attracted increasing attention due to their potential carcinogenicity and adverse health effects. Activated carbon is widely used for PAHs removal owing to its well-developed pore structure and excellent adsorption capacity; however, the adsorption selectivity toward PAHs and the retention of beneficial lipid components remain insufficiently understood. In this study, peanut oil was selected as a model system to elucidate the structure-activity relationship between activated carbon surface characteristics and PAH adsorption behavior. The effects of particle size, pore structure, and surface oxygen-containing functional groups on PAH removal efficiency and the retention of endogenous nutrients were investigated. The results showed that reducing activated carbon particle size and increasing the specific surface area, total pore volume, and mesopore volume significantly improved PAHs removal performance, indicating that enhanced pore accessibility and mass transfer efficiency contributed to adsorption enhancement. Among the tested pore structures, pores in the range of 1.6-2.9 nm were identified as the major effective adsorption region for PAHs. This pore-size range closely matched the molecular dimensions of tocopherols (1.8-2.6 nm) but was largely incompatible with those of sterols (2.5-3.6 nm). Therefore, regulation of pore structure can facilitate efficient PAHs removal while better preserving bulky sterols, although partial tocopherol loss may occur simultaneously due to competitive adsorption. Furthermore, the introduction of oxygen-containing functional groups (-OH, -COOH, and C=O) onto the activated carbon surface enhanced the adsorption stability of PAHs, with adsorption energies ranging from −0.866 to −0.911 eV. Surface functionalization also promoted the preferential adsorption of PAHs and reduced the adsorption loss of tocopherols (−0.598 to −0.909 eV), but it increased the nonspecific adsorption of sterols (−0.908 to −1.031 eV). Overall, pore structure and surface chemistry synergistically regulated adsorption selectivity and oil quality retention. This study provides theoretical guidance for the rational design and screening of highly selective adsorbents for PAHs purification in edible oils.