There has been a continuous increase in the global incidence of obesity. Rosa roxburghii Tratt (RRT), a plant with medicinal and edible uses, contains active components that can alleviate obesity, indicating an anti-obesity potential. This research sought to investigate the anti-obesity effects of RRT fruit extract (RRTE) and elucidate the underlying mechanisms and components responsible for its action. RRTE was obtained by enriching the active ingredient in RRT and used to treat HepG2 cells. RRTE alleviated cellular lipid accumulation, reduced reactive oxygen species production, restored cellular mitochondrial function, and enhanced energy metabolism. Network pharmacology combined with molecular docking was used to determine the targets, components, and mechanisms, which were validated through in vitro experiments. p-Coumaric acid and ethyl caffeate were identified as lipid-lowering active components that may reduce lipid accumulation and alleviate obesity through the PI3K-Akt and PPAR signaling pathways.