Currently, diabetes is the fourth most common disease causing death in the world, and the World Health Organization has called it the “disaster of the 21st century”. Diabetes mellitus is an endocrine metabolic disease, caused by absolute or relative insulin deficiency and reduced sensitivity of target cells to insulin, resulting in disorders of glucose, protein, fat and secondary water and electrolyte metabolism, with hyperglycemia as its important clinical feature; type 2 diabetes mellitus (T2DM), also known as adult-onset diabetes mellitus, mostly develops after the age of 35-40, accounting for more than 90% of diabetic patients. Due to the coronary heart disease, nephropathy, retinopathy and neuropathy caused by diabetes is the main cause of death and disability of patients. Moreover, according to WHO, the incidence of diabetes in the world is increasing significantly year by year. Therefore, the World Health Organization has called it “the disaster of the 21st century”. Diabetic patients are in urgent need of a treatment that can control diabetes and its complications well. Diabetes is an ancient medical disease, and traditional treatment methods include diet control, exercise, oral hypoglycemic drugs and insulin injections, etc. However, these treatment methods can hardly cure diabetes fundamentally, maintain the long-term stability of patients’ blood sugar, and prevent the occurrence and development of various complications of diabetes fundamentally. Strict dietary control and repeated fluctuations of blood glucose levels cause continuous mental stress to patients and affect the quality of life. Despite patients’ active cooperation with treatment, most patients develop complications of varying degrees after 5 years of disease. Patients urgently need a treatment that provides good control of diabetes and its complications. The clinical success of gastric diversion surgery (GBP) has led to a new way to treat diabetes. Gastric diversion surgery In the 1950s, bariatric surgery began to be used for the treatment of obesity, with significant improvement in type 2 diabetes after surgery, a phenomenon that did not attract much attention. It was not until 1998, when the world’s leading academic journals reported the results of bariatric surgery, once again proving the fact that diabetes was cured in patients after gastric diversion surgery, that the academic community paid great attention to this phenomenon. Since then, gastric diversion surgery has been promoted in Europe and America. Gastric diversion surgery is similar to general gastrointestinal surgery and is not a major operation. The jejunum is cut at a distance of 3O to 50 cm from the flexor ligament. The distal end is anastomosed in the remnant stomach. The proximal end is 5O-150 cm away from the gastric-jejunal anastomosis and the jejunum is anastomosed end-laterally. Therefore, it is also called ROUX-EN-Y-GBP. The mechanism of gastric diversion surgery (GBP) for the treatment of diabetes mellitus is gradually deepening, but any is not very clear. The main mechanisms may be: (1) reduced food intake and absorption, thus reducing energy intake and glucose metabolic load; (2) lowering the patient’s body weight and reducing insulin resistance due to fat accumulation from simple obesity; (3) altering the secretion of hormones in the gut-insulin axis after gastrointestinal tract reconstruction, thus improving glucose metabolism. The third one is mainly supported at present, but still needs continuous and in-depth research. The efficacy of gastric diversion surgery (GBP) in the treatment of diabetes mellitus is definite. The Swedish obesity research program SOS, which followed more than 3,000 patients with type 2 diabetes mellitus and concomitant obesity for 10 years after surgery, found that this group of cases did not reflect abnormally in such a long time span, and their blood glucose remained normal, with a cure rate of more than 90%; another 6-year follow-up after surgery in 2,410 patients with type 2 diabetes mellitus reported by Robert and Rutledge showed that In early 2009, the American Diabetes Association has included gastric diversion surgery for diabetes into the diabetes treatment guidelines, and now, Sweden, the Netherlands, Italy and other countries have officially introduced the surgery into the clinic, and as many as 400,000 patients have received the surgery. In 2010, China also formulated the draft guidelines for the surgical treatment of diabetes in China (2010). Laparoscopic gastric diversion surgery (GBP) has outstanding advantages in treating diabetes and is the future direction of development. Minimally invasive surgery is one of the directions of surgical development in the 21st century. Since the first successful application of laparoscopy to cholecystectomy by Mouret in France in 1987, minimally invasive surgery represented by laparoscopic techniques has flourished and gradually penetrated into all fields of abdominal surgery. Various types of surgery, ranging from small appendectomies and infertility probes to large pancreaticoduodenectomy resections, have been continuously tried and proven to have the advantages of minimally invasive and rapid postoperative recovery. Laparoscopic gastric diversion surgery (GBP) for the treatment of diabetes is as effective as cesarean surgery and has the advantages of less trauma, less bleeding, faster recovery, and relatively few complications. The number of cases of laparoscopic gastric diversion surgery (GBP) for the treatment of diabetes mellitus in China is relatively small, and there is still a need to accumulate experience and standardize the operation. GBP surgery is a new surgical technique that is widely performed abroad, but only Beijing, Shanghai, Guangzhou and other regions in China are gradually starting to develop this new technique, and mainly open surgery. Foreign developed countries are now mainly laparoscopic and have accumulated a lot of experience. The applicant has participated in many cases of open gastric diversion surgery (GBP) for diabetes mellitus in his original unit, and the results were satisfactory. However, laparoscopic gastric diversion surgery for the treatment of diabetes requires experienced surgeons to complete. Therefore, there are still few hospitals performing it, and there is still a need to accumulate experience and standardize the operation.