Abstract: Based on the single factor experiment, the response surface method was used to optimize the preparation process of duck gizzard antioxidant peptide.In the pre-screening of the best protein for enzymatic hydrolysis of duck gizzard, papain was obtained as the best enzyme for enzymatic hydrolysis of duck gizzard protein.The optimum conditions were as follows: the time of enzymolysis was 4.0 h, the amount of enzyme was 0.5%, the enzymolysis temperature was 55 ℃, and the ratio of solid to liquid was 1∶ 3 g/m L.Under these conditions, the hydrolyzate degree of hydrolyzed duck gizzard protein was 28.30% and the DPPH·clearance rate was 75.10%.The results showed that the duck gizzard antioxidant peptide preparation process was feasible, there was no correlation between the hydrolysis degree of duck gizzard and DPPH· scavenging ability.