Objective: In this study, semen ziziphi spinosae protein hydrolysates （SZPHs） with good antioxidant activity were used as the research object. Methods: By simulating gastrointestinal digestion in vitro, the semen ziziphi spinosae protein hydrolysates gastrointensive digest （SZPHs-GD） was obtained. The amino acid composition and antioxidant activity of SZPHs before and after digestion were analyzed in order to explore the effect of internal environment on the structure and activity of SZPHs. Results: The results showed that after simulated digestion in vitro, the content of hydrophobic amino acids in SZPHs-GD decreased by 1.51%, the content of hydrophilic amino acids and negatively charged amino acids increased by 0.83% and 2.11%, respectively, and the content of essential amino acids had no significant change; the results of molecular weight distribution showed that the molecular weight of szphs and szphs GD were mainly below 5 kDa, and the proportion of <5 kDa components increased after simulated digestion; the results of antioxidant activity test show that, after simulated gastrointestinal digestion in vitro, the highest DPPH radicals scavenging rate of SZPHs-GD was 81.25%, ABTS⁺ radicals scavenging rate was 90.40%, superoxide radicals scavenging rate was 47.51%, hydroxyl radicals scavenging rate was 32.66%. Conclusion: SZPHs-GD still had good amino acid composition and antioxidant activity after simulating gastrointestinal digestion.