Abstract: In this research,salmon skin collagen oligopeptides(SSCP)were prepared by enzymatic hydrolysis using salmon skin and subjected to in vitro digestion experiments. Through molecular weight distribution analysis,DPPH free radical scavenging activity,hydroxyl radical scavenging activity,total antioxidant capacity(ABTS method)and reactive oxygen species(ROS)experiment,the antioxidant properties of SSCP were explored before and after in vitro digestion. The results showed that the weight average molecular weight of SSCP decreased slightly after the simulated digestion experiment,with a change of no more than 4%;before and after pepsin digestion,the IC₅₀ values of DPPH free radical scavenging activity were 11.1 and 12.3 mg/mL,respectively,and before and after trypsin digestion,the IC₅₀ values were 12.5 and 14.6 mg/mL,respectively;before and after pepsin digestion,IC₅₀ values of hydroxyl radical scavenging activity were 12.2 and 13.2 mg/mL,respectively,and before and after trypsin digestion,IC₅₀ values were 10.7 and 11.5 mg/mL,respectively;after pepsin digestion,the total antioxidant capacity decreased by no more than 13%,and after trypsin digestion,the total antioxidant capacity decreased by no more than 19%;after pepsin digestion,the ROS scavenging activity increased by no more than 3%,and after trypsin digestion,the ROS scavenging activity increased by no more than 5%. This indicated that SSCP had good digestive stability and antioxidant activity,which provided a theoretical basis for their development in antioxidant functional food.