Abstract: In the present study, the cucumber peel polyphenols was ultrasonic-assisted extracted and the extraction process was optimized through response surface methodology, and their antioxidant activities were further studied. The extraction yields of polyphenols were used as the response surface value in Box-Behnken design and response surface optimization, and the ultrasonic temperatures, ethanol concentrations, liquid-to-material ratios,and ultrasonic times were selected as independent variables, then the antioxidant activities of scavenging hydroxyl radicals（·OH） and 1,1-diphenyl-2-trinitrophenylhydrazine free redicals（DPPH·） were evaluated. The results showed that the optimal parameters for cucumber peel polyphenols extraction were determined as follows:ultrasonic temperature of 65 ℃, ethanol concentration of 62%, liquid-to-material ratio of 26∶1（mL/g）, and ultrasonic time of 31 min. Under these conditions, the actual value of polyphenols extraction yield was（10.29±0.14） mg/g, and the relative error between theoretical value and actual value was 0.39%, which indicated that the obtained extraction process parameters by response surface method were feasible with high reliability. The IC50 values of·OH and DPPH·scavenging rates of cucumber peel polyphenols were 116.60 mg/L and 57.41 mg/L, respectively, indicating that cucumber peel polyphenols showed good antioxidant activities, which was positively correlated with their concentrations.This study provided a theoretical basis for the development of cucumber peel polyphenols as natural antioxidants.