The invention belongs to the technical field of edible vegetable oil processing and extraction, and particularly relates to passion fruit seed oil and a preparation method thereof, wherein the preparation method comprises the following steps: (1) crushing; (2) pretreating raw materials; (3) performing enzymolysis; (4) performing enzyme deactivation treatment; (5) performing demulsification; (6) performing centrifugal separation; and (7) obtaining a finished product. According to the method, an aqueous enzymatic extraction process is adopted, no additives and solvent residues are left except for food enzymes, the treatment temperature and time are strictly controlled in the processing process, and it is guaranteed that natural effective components in the passion fruit seeds are reserved. Meanwhile, the raw materials are pretreated after being crushed, the oil extraction rate is increased to the maximum extent by means of demulsification after enzymolysis, and the problem that the oil extraction rate is low due to the fact that water-oil emulsions are difficult to separate is effectively solved. The passion fruit seed oil prepared by the method is clear, transparent and bright in color and luster, has sour and sweet fruit fragrance, is mild in texture, not greasy, free of irritation, good in quality, safe and stable, and nutrient substances such as linoleic acid, oleic acid and polyphenol are well reserved.