Abstract: As a free trade port, Hainan is rich in tropical fruits and marine resources, but there has been no research on the development of their combinations. Acerola cherries are known as "red precious fruit" and "fruit of life". The V_C content of an acerola cherry is 190 times that of conventional cherries. Therefore, acerola cherries have strong antioxidant capacity, which can effectively scavenge free radicals and reduce their damage to the human body. However, because acerola cherries are difficult to plant, expensive, perishable, difficult to store, their development is limited, resulting in a single product of acerola cherries and difficulty in market circulation. The umami substances in oysters contain a variety of vitamins and minerals and can promote appetite, besides, oyster peptides are peptide mixtures containing short peptide chains by enzymatic hydrolysis of oysters. They are easy to digest and absorb, and have outstanding antioxidant activities. However, such seafood has a strong smell, limiting their development as beverages. Therefore, this study aimed to further improve the effective use of marine products and acerola cherries in Hainan Province and to broaden the range of compound beverages on the market. This study used acerola cherries and oysters as the main raw materials to develop a polypeptide compound beverage. Acerola cherry juice, sucrose, citric acid, and oyster polypeptide extract were selected as variables, and a single variable was used for the experiment on the basis of the basic technology. On the basis of the single factor test, according to the Box-Behnken central combination test design principle, the 4-factor 3-level response surface analysis method was used to further optimize the ratio of the composite beverage, and the antioxidant activity of the composite beverage was determined. Under the conditions of oyster peptide 8.00 g/100 mL, acerola cherry juice 19.94%, sucrose 8.07%, and citric acid 0.23%, the comprehensive score of acerola cherry oyster polypeptide compound drink was the highest, and its antioxidant activity was 97.6%. The compound beverage improves the quality and antioxidant activity of acerola cherry beverage. The combined antioxidant effect of acerola oyster polypeptide is stronger than that of the single one. This also provides a theoretical basis for the development of high antioxidant compound beverages. Meanwhile, it can also promote the development of a deep processing of acerola cherries, laying a foundation for the further development and utilization of seafood in the Hainan Free Trade Port.