The invention provides a sheep placenta antioxidant polypeptide as well as an enzymatic hydrolysis preparation method and an application thereof. With sheep placenta leftovers as raw materials, the sheep placenta polypeptide, which is high in antioxidant activity, is prepared by conducting enzymatic hydrolysis by virtue of papain, then conducting separation and purification by virtue of macroporous adsorption resin, an ultrafiltration membrane, sephadex gel chromatography and semi-preparative RP-HPLC reversed-phase high-performance liquid chromatography, collecting an obtained material and freeze-drying the material, wherein the amino acid sequence of the sheep placenta polypeptide is shown as Glu-Pro-Val-Ser-His-Phe. According to the method provided by the invention, sheep placenta processing wastes can be effectively utilized, so as to improve an added value and increase an economic benefit, and the method has the advantages of being high in product activity, convenient and feasible in preparation process, environment-friendly and the like; with the application of the method provided by the invention, the natural polypeptide, which is high in antioxidant activity, can be obtained, and the prepared polypeptide, replacing an artificially synthesized antioxidant, such as a functional raw material in anti-aging cosmetics, can be used for preparing lotions, night creams, eye creams, gels, essences, facial masks and the like.