Yeast mannoprotein is a non-fibrous glycoprotein localized on the outermost layer of yeast cell walls. As a natural functional ingredient, its commercial application is limited and currently only used as a wine stabilizer. To advance the development and broader commercialization of mannoprotein, this paper briefly outlines its structural characteristics, including the peptide chain, core region, and outer chain composition. The peptide chain forms the backbone of mannoprotein, while the core and outer chains are composed of various carbohydrate portions, predominantly mannose residues. This unique structure contributes to the diverse biological activities of mannoprotein. The advantages and disadvantages of acid, alkali, enzyme, and physical methods for extracting yeast mannoprotein are discussed. Acids and bases are effective for extracting yeast mannoprotein, but may compromise its structural integrity, while enzymatic extraction is less destructive, preserving the structure but with a higher cost. A systematic review is conducted on the biological activities of yeast mannoprotein in improving intestinal health, stimulating immunity, antioxidation, lowering blood lipids, and adsorbing mycotoxins, as well as its applications in the production of oligosaccharides, bio emulsifiers, nutritious and healthy foods, fruit preservation, animal nutrition, and wine production. Finally, research progress on the synthesis pathways of N-glycosylation and O-glycosylation in yeast mannoprotein and strategies for controlled gene modifications provide new technologies for efficient production of mannoprotein. Despite these advances, the production and application of yeast mannoprotein still face challenges. The diversified structures of yeast mannoprotein pose challenges to research. The action mechanism, spatial structure, molecular weight, and interrelationship of yeast mannoprotein are not fully understood. Future research should focus on elucidating the relationship between the structure of yeast mannoprotein and its biological activity. Combined with the application of biosynthesis technology, it is expected to promote the development of the yeast mannoprotein industry and enhance its applications in fields such as foods, cosmetics, medicines, etc.