Abstract: Objective: To study the optimal process conditions of flash extraction and antioxidant activity of American ginseng flower polysaccharides (AGFPs). Methods: American ginseng flower (AGF) as the raw material, the effects of extraction voltage, liquid-material ratio, and extraction time on the yield of AGFPs were explored. The flash extraction process of AGFPs was improved by response surface methodology. The scavenging effect on DPPH and hydroxy free radicals and total reduction capacity of AGFPs were determined to assess the antioxidant activity of AGFPs. Results: The optimal extraction conditions were determined as 130 V of extraction voltage, 30:1 mL/g of liquid-material ratio, and 100 s of extraction time, resulting in an AGFPs yield of 11.12%±0.23%, which agreed with the model prediction. The AGFPs exhibited significant scavenging effects on DPPH and hydroxyl radicals, with IC₅₀ values of 1.34 mg/mL and 1.42 mg/mL, respectively, and had a certain reducing power. Conclusion: These results suggested that flash extraction was an efficient and rapid method for obtaining AGFPs from AGF, and that AGFPs had promising antioxidant potential for further applications. This study can provide a theoretical basis for the development and application of AGF.