The experiment was aimed to optimize the extraction technology of polyphenols from corn cob. The types of natural deep eutectic solvents for extraction were determined through screening experiments. Based on the results of single-factor experiments, the water content of the NADESs, liquid-to-solid ratio, ultrasonic power, and ultrasonic temperature were set as variables, with the extraction yield of corn cob polyphenols as the response value, and the response surface method was employed to optimize the extraction process. The scavenging abilities of polyphenol extracts from the NADESs and 70% ethanol on 1, 1-diphenyl-2-trini-trophenylhydrazi-ne (DPPH) radicals and 2, 2-diazodi bis (3-ethylbenzothia-zole-6-sulfonic acid) diamine (ABTS) radicals was compared. The results showed that at a NADESs water content of 31%, a liquid-to-solid ratio of 28 mL/g, an ultrasonic power of 350 W, and an ultrasonic temperature of 61 ℃, the extraction yield of corn cob polyphenols reached the highest level of 17.49 mg/g, and the antioxidant activity of the extracted product was stronger than that of the 70% ethanol extract. The study indicates that the extraction process of polyphenols from corn cob was stable and reliable, which can provide reference for the efficient extraction of polyphenols from corn cob. [ABSTRACT FROM AUTHOR]