Objective To investigate the effects of different extraction methods on the efficacy, chemical composition, and functional group characteristics of flavonoids in Lycium barbarum leaves.Methods This study comparatively analyzes the effects of three methods-ultrasound-assisted ethanol extraction (UAE), microwave-assisted ethanol extraction (MAE), and aqueous two-phase system (ATPS)-on the yield, composition, and in vitro antioxidant activity of flavonoids from L. barbarum leaves.Results UAE and MAE achieve the highest yield of flavonoids from dried L. barbarum leaves. The main components are rutin, quercetin, chlorogenic acid, and kaempferol. The antioxidant capacity of the flavonoid extract from dried L. barbarum leaves is significantly higher than that of fresh samples, and the UAE extract has the highest DPPH radical scavenging rate (84.31%) and the strongest ferrous ion-reducing ability (26.23%).Conclusion The dissolution efficiency of flavonoids varies under different extraction methods, and there is a significantly positive correlation between the flavanol structure and antioxidant activity.