High-efficiency shrimp immunomodifier

The invention discloses an active oligopeptide and polysaccharose composite immunomodifier using compound amino acid as a feed flavoring agent, which is prepared by making full use of waste from Paphia undulata processing plants, determining obvious influence factors through an orthogonal experiment, controlling a hydrolysis degree to be 34 to 40 percent and an average polypeptide length of about3, optimally extracting active sulfated polysaccharide gracilaria tenuistipitata by a ultrasonic method, and adding composite vitamin and other minor ingredient according to a formula design principle. The immunomodifier can induce the appetite of fish and shrimps to take food, improve appetite and growth, increase fish and shrimps yield, improve immunocompetence of fish and shrimps, reduce the fish and shrimp diseases, save cost and be directly mixed in feed with stirring and is convenient in batch charging.