2,3,5,4,-Tetrahydroxystilbene-2-O-β-d-glucoside (TSG) is the main active constituent of the traditional Chinese medicine, Polygonum multiflorum; it was discovered that the compound has various biological activities and medicinal value including anti-aging, antioxidative (via scavenging free radicals), antihypercholesterolemic, anti-atherosclerotic, anti-inflammatory, hepatoprotective, and anti-tumor effects. TSG aids in prevention and treatment of Alzheimer's disease. With its wide clinical application, its separation and purification has become a research hotspot. In this paper, the pharmacological action, extraction process, and application prospects of TSG were reviewed in order to provide references for further development of TSG.