Response surface method (RSM) was used to optimize the extraction process of mung bean polyphenols and study its antioxidant activity. The results showed that the optimal extraction process was 112 (g/mL), extracted at 46 ℃ for 1.6 h. The amount of polyphenol extracted under the control of these conditions was 11.74 mg/g. The rate of polyphenol superoxide anion free radical scavenging in mung bean was 58.5%, and that of the nitrite ion clearance was 26.0%. Therefore, it inclined that the polyphenols from mung bean had good antioxidant activity.