The present invention relates to biotechnology field, disclosing a method for preparing a sexual function-improving oyster peptide and the use thereof. The method comprises: grinding oyster flesh, calcium salt and water to obtain oyster flesh pulp enzymatic hydrolyzing oyster flesh pulp, centrifuging and collecting the supernatant to obtain an oyster enzyme-hydrolyzed raw solution decoloring the oyster enzyme-hydrolyzed raw solution and removing impurities to obtain a fine oyster peptide solution concentrating and spay drying the fine oyster peptide solution to obtain the oyster peptide. In the present invention, oyster flesh is pretreated with calcium salt prior to enzymatic hydrolysis to activate and releases oyster endogenous enzymes therefore reducing the use of enzymes in subsequent enzymatic hydrolysis at the same time, cooperating with the endogenous enzymes, two steps enzymolysis is carried out to produce an oyster peptide with a strong antioxidant activity and a significant improvement in sexual function.
