Sweet tea is a sweet plant that serves triple functions as tea, sugar, and medicine, which is rich in bioactive components, including rubusoside, polyphenols, flavonoids and amino acids. It has many bioactive functions such as antioxidant and anti-aging, lowering blood sugar and blood lipid, antibacterial and anti-allergic, anti-cancer and anti-tumor functions, thereby having great potential in advancing public health and promoting food industry. This paper summarizes the extraction methods, functions and application of different active components in sweet tea, and points out the current research challenges and future research directions. In conclusion, this review provides more valuable references for the development and utilization of sweet tea.