With the research on the pathogenesis of diabetes, domestic and foreign scholars have put forward two more theories on the etiology of diabetes, namely the foregut theory and the hindgut theory, which believe that the K cells in the upper gastrointestinal tract of diabetic susceptible persons produce “insulin resistance factor” after food stimulation, causing insulin resistance in the body, which is considered to be the main cause of type 2 diabetes. L cells in the lower GI tract can produce factors that increase insulin action, such as insulin-like growth factor-1, etc., stimulated by food, which can lower blood glucose. This method not only cures diabetes, but also has a cure rate of more than 83% and an efficiency rate of 98%, with better long-term results than recent ones. At the same time, 60% of diabetes combined with hypertension, fundopathy, diabetic nephropathy and other complications have been improved to varying degrees, and even cured. Indications for this surgery: 1. meeting the diagnostic criteria of type 2 diabetes; 2. history of less than 15 years; 3. islet function in compensatory phase (plasma insulin level > 1/3 of normal value); 4. age ≤ 65 years. Contraindications to surgery: 1. advanced diabetes mellitus, islet failure, autoimmune diabetes mellitus (LADA); 2. serious organic diseases (coronary heart disease, cerebral infarction, renal failure, heart failure, severe hypertension, etc.) that cannot tolerate surgery; 3. gastrointestinal tract disorders, moderate to severe diabetic gastroparesis; 4. age > 65 years.