To　achieve　the　high-value　utilization　of　squid　skin　obtained　from　squid　processing,　this　study　utilized　an　enzymatic　approach　to　prepare　protein　peptides.　The　enzymatic　hydrolysis　parameters　were　optimized　using　single　factor　and　response　surface　tests,　with　the　concentration　of　peptide　and　trichloroacetic　acid-nitrogen　soluble　index　(TCA-NSI)　serving　as　evaluation　criteria.　The　amino　acid　composition,　molecular　weight　distribution,　peptide　sequence,　antioxidant　activity,　and　in　vitro　simulated　digestive　properties　of　the　prepared　protein　peptides　were　also　thoroughly　characterized.　The　results　showed　that　the　optimal　conditions　for　enzymatic　hydrolysis　were　as　follows:　Enzymatic　temperature　of　43.50　℃,　enzymatic　time　of　100　minutes,　enzymatic　pH　of　7.50,　trypsin　to　alkaline　protease　ratio　of　2:1,　and　enzyme　dosage　of　4000　U/g.　Under　these　specified　conditions,　the　TCA-NSI　achieved　a　value　of　89.02%±0.66%.　The　prepared　protein　peptides　exhibited　a　well-balanced　amino　acid　composition,　with　an　essential　amino　acid　index　(EAAI)　value　of　0.90.　Furthermore,　the　prepared　protein　peptides　encompassed　a　total　of　43　polypeptide　sequences,　with　38　of　these　segments　exhibiting　molecular　weights　below　1800　Da.　The　IC50　values　for　scavenging　DPPH　radical,　ABTS+　radical,　and　hydroxyl　radical　were　determined　to　be　0.61,　0.28　and　1.95　mg/mL,　respectively.　Notably,　the　antioxidant　activity　remained　favorable　even　after　undergoing　simulated　gastrointestinal　digestion　in　vitro.　These　findings　serve　to　establish　a　solid　theoretical　basis　for　the　advancement　and　exploitation　of　byproducts　derived　from　squid　processing,　as　well　as　their　subsequent　value-added　utilization.　©　2024　Editorial　Department　of　Science　and　Technology　of　Food　Science.　All　rights　reserved.