Insulin (INS) is the only hormone in the body that can lower blood glucose and is secreted by pancreatic beta cells. Pancreatic islet β-cells are stimulated by endogenous or exogenous substances, such as glucose, lactose, ribose, arginine, hyperglycemia, etc., they will secrete a protein hormone, which is insulin. Normal human beings secrete about 25-50 units of insulin into the blood every day, and insulin is not only the only hormone in the body that can lower blood glucose, but also promotes the synthesis of glycogen fat protein. According to eating or not, the physiological secretion of insulin in normal people mainly consists of two parts: basal insulin secretion and meal-time insulin secretion, whose secretion accounts for about 50% of the total secretion of the whole day, respectively. Insulin secretion can be regulated by blood glucose concentration of amino acids and fatty acids, as well as hormones and nerves.