With the development of medical science and technology, gastric diversion surgery, mainly for the treatment of morbidly obese type 2 diabetic patients, has been practiced in the United States since the 1980s, and it was unexpectedly found that patients could obtain complete remission of diabetes after surgery. Clinical studies by domestic and foreign experts for decades have confirmed that surgical treatment of type 2 diabetes is effective, with a surgical efficiency rate of 95% and a complete remission rate of over 83%. Why is weight loss surgery effective? First of all, it is important to understand the mechanism of surgical treatment of diabetes. One of the main mechanisms of surgical treatment of diabetes is that it reduces food intake and absorption, thus reducing energy intake and glucose metabolic load. All bariatric surgery patients will have very low caloric intake in the short term. Previous studies have shown that 1 week of very low caloric intake can achieve the effect of reducing insulin resistance, followed by weight loss of patients, which also has long-term effects on reducing intra-abdominal fat and insulin resistance. For example, gastric bypass surgery, known as the “gold standard procedure” for diabetes, is a surgical procedure that reduces the volume of the stomach, shuts down most of the stomach’s function, and changes the structure of the intestine, thereby further reducing digestive capacity and controlling absorption. Because the gastrointestinal tract is reconstructed, the secretion of hormones in the intestine-islet axis is altered, thus improving glucose metabolism.