Stevia leaf, belonging to the Asteraceae family, are perennial herbaceous plants. The main planting bases in China are Jiangsu and Anhui province. Stevia leaf contain a sweet substance called "steviol". Refined steviol is a colorless and odorless crystal with a sweetness 200 times that of sugar, extremely low in calories, easily soluble in water, and does not increase the body's heat and sugar burden; It can be widely used in various food, beverage, pharmaceutical, and daily chemical industries.