Radix Puerariae (RP) is an important medicinal and edible food in China. The country has an abundant RP output and a large number of RP consumers. Isoflavones are the most abundant and bioactive ingredients in RP. This article comprehensively reviews the composition and structure of isoflavones from RP, and systematically expounds their functions such as anti-hypertension, anti-hyperlipidemia, anti-hyperglycemia and antioxidant activity, alleviating a hangover, liver protection, alleviating post-menopausal osteoporosis and improving cognition as well as the underlying mechanism of action. The current research hotspots and problems existing in the field of research on RP isoflavones and their significance to the development of drugs and functional foods containing RP isoflavones are also proposed. We believe that this review will provide useful ideas and guidance for the basic research on RP and the commercialization of research achievements in this field.