In this study, the ultraviolet (UV) enhanced γ‐Fe2O3@Carbon composite (γ‐Fe2O3@C) persulfate (PS) activation system was successfully constructed for quinoline degradation. Quinoline can be effectively degraded with the removal efficiency of 99 % and TOC removal efficiency of 86 % in 60 min at pH 7.5 due to the increased contribution of SO4.− and .OH caused by the assistance of UV irradiation in the γ‐Fe2O3@C/PS system. Control experiments showed that the quinoline removal efficiency might be primarily restricted by the limited PS dosage and the system had a wide pH application range of 3∼11, good tolerance and strong anti‐interference ability. In the presence of the reactive oxygen species (SO4.−, .OH and 1O2), quinoline was first decomposed into formic acid, aniline, ethylbenzene and other intermediate products through hydroxylation, oxidative dehydrogenation and ring‐opening reactions and then most of them were mineralized into carbon dioxide and water eventually.