DPPH自由基的EC50值为0.155g/（100mL）。Protease screening was studied to prepare potato antioxidant peptide using the enzymolysis method. With potato dregs as the raw material and the scavenging rate of hydrolysate to the DPPH radical as an index, neutral protease was screened out from the following six kinds of protease: papain, flavor protease, neutral protease, alkaline protease, trypsin and pepsin. The optimum hydrolysis conditions obtained by the experiments were substrate concentration 4 g/(100mL), 7% enzyme-substrate ratio, pH value 8.0, 50°C and 90min reaction time. After being diluted 20 times, the scavenging rate of hydrolysate liquid to the DPPH radical reached 72%. The EC50 value of hydrolysate scavenging the DPPH radical was 0.155 g/(100mL).