Abstract: As one of the main active ingredients of garlic, garlic polysaccharide has many biological activities, such as enhancing immunity, antibacterial, antiviral, antioxidant, hepatoprotective, hypolipidemic, hypoglycemic, etc., and has a broad application prospect. The extraction methods of garlic polysaccharides are most common by hot water method, enzyme method and ultrasound-assisted method. It is found by structural determination that garlic polysaccharide is a heteropolysaccharide composed of fructose, glucose, galactose, mannose, galacturonic acid, etc. Chemical modifications such as acetylation, selenization and phosphorylation can increase the antioxidant and other biological activities of garlic polysaccharide. This paper systematically summarizes the current research status of garlic polysaccharides from the perspectives of extraction, structure determination, chemical modification and bioactivity of garlic polysaccharides, and in the future, attention should be paid to the conformational relationship between polysaccharide structure and bioactivity, and the efficacy mechanism of garlic polysaccharides should be explored in depth, with a view to providing theoretical references for the development and utilization of garlic polysaccharides as functional products.