Obesity has now become a global epidemic disease, seriously threatening human life health and quality of life, treatment includes exercise therapy, diet control, drug therapy and surgery, etc., of which weight loss surgery is the only way to make patients with severe obesity obtain long-term, stable weight loss effect, and is also the treatment of obesity-related type 2 diabetes, primary hypertension, hyperlipidemia and obstructive respiratory sleep apnea and other metabolic disorders It is also the most effective treatment for metabolic disorders such as obesity-related type 2 diabetes, essential hypertension, hyperlipidemia and obstructive apnea. Bariatric surgery first began in the 1950s and has been introduced to China since 2000. With the maturation and development of clinical application of laparoscopic technology, laparoscopic surgery for obesity has become a popular trend. Common complications: the incidence of complications is about 5%, and the perioperative mortality rate is about 0.1%. Nausea and vomiting: they are the most common complications in the first year after surgery. Nausea and vomiting in the immediate postoperative period are usually caused by reaction to anesthetic drugs, obstruction of the small gastric bursa outlet due to tight banding, postoperative gastric wall edema or improper placement of the banding. Gastric wall edema can be relieved by conservative treatment, while outlet obstruction requires adjustment of water injection to relieve the obstruction, and improper placement of the band requires surgical adjustment of the position. In our hospital, the gastric tube is routinely left in place for 24 hours after surgery, and after the upper gastrointestinal tract is confirmed to be appropriately positioned by pantopamine imaging and without outflow tract obstruction, the gastric tube is removed and a liquid diet is fed. Incisional infection: Obese patients have thicker abdominal fat, which makes the surgery easy to form fat liquefaction necrosis and local infection foci, especially the incision where the pump is placed. At the same time, because patients are mostly combined with diabetes, it is easy to cause secondary infection. Measures such as prophylactic use of antimicrobial agents, minimal use of subcutaneous electric knife, and strict postoperative control of blood sugar can be taken to reduce the incidence of incisional infection. Displacement of the gastric band: Mostly caused by unsatisfactory fixation of the band during surgery, and the band needs to be removed if the symptoms are serious. The incidence can be reduced by fixing and embedding the gastric band exactly during the operation. Displacement of the injection pump: The injection pump should be routinely placed on the surface of the anterior sheath of the rectus abdominis muscle in the left upper abdomen, fixed with 4 stitches of non-absorbable silk at all four corners, and embedded in the subcutaneous fat layer. Usually the displacement of the injection pump is mainly caused by inaccurate fixation, and the exact fixation and tension-free fixation during the operation is the key to prevent the displacement of the injection pump. Gastric bursa dilatation: Mostly due to the excessive volume of the gastric bursa left in place during surgery and inaccurate fixation of the band. To control the volume of gastric bursa to 10-15 ml and to embed the gastric band at the same time is the fundamental measure to reduce the dilatation of gastric bursa. Gastric bursa dilatation can be treated by laparoscopic repositioning of the band. Gastric banding gastric wall erosion: a serious complication that may be related to an individual’s allergic reaction to silicone or too tightly encapsulated gastric antral banding. The gastric band needs to be removed and the damaged gastric wall repaired. Weight loss effect: 30% to 40% of the overweight portion of body weight can be lost 1 year after surgery, 50% 2 years after surgery, and 50% to 60% after 3 years after surgery, reducing preoperative BMI by 25%. The first water injection can be started 1 month after surgery, and thereafter the total water injection will be decided according to the weight loss, and the more satisfactory weight loss index is 0.5-1.0 kg per week. In 2000, Mason et al. first proposed gastric bypass surgery, which is the earliest surgical treatment for obesity. in 1977, Alden [5] proposed to perform Roux-en-Y gastrointestinal bypass surgery for weight loss. in 1994 LRGB is considered the gold standard for bariatric surgery in the United States, accounting for approximately 70% of bariatric surgery in the U.S. In 2001, Rutledge first reported laparoscopic mini gastric bypass, which is comparable to RYGBP in terms of surgical treatment, but with reduced surgical operations, shorter operative time, and lower complication rates. The results are better, but compared with LAGB, the operation is complicated, the learning curve is long, the trauma is large, the complication rate is high, the postoperative period requires related nutrient monitoring and supplementation, and the perioperative mortality rate is higher. Because of the high incidence of gastric diseases in our population, and LRGB can lead to restricted examination of the large gastric sac after surgery, such as inaccessible gastroscopy, this procedure should be used with caution for people with a high prevalence of gastric diseases. Also LRGB can lead to more effective control of some chronic diseases such as long-term type 2 diabetes and essential hypertension. Therefore, it may be an option for patients with these diseases, taking into account the risk/benefit ratio. Common complications: The complication rate is about 5% and the perioperative mortality rate is about 0.5%. Nutritional deficiencies: The most common complications of LRGB include micronutrient and vitamin deficiencies, such as iron deficiency, anemia, and hypokalemia. Anemia can occur due to malabsorption of iron and vitamin B12 as the procedure leaves most of the gastric cavity open. The food does not pass through the duodenum, and the absorption of calcium is affected. Patients need lifelong oral medication to supplement these elements to avoid such complications. Gastrointestinal fistula: It occurs mostly in the gastrojejunal anastomosis and is mainly associated with the LRGB learning curve. Strict lumpectomy training and surgical access system can significantly reduce its incidence. Anastomotic stenosis: mainly occurs at the gastrojejunal anastomosis. Early occurrence may be related to local tissue edema, which can be relieved by conservative treatment. Later occurrences can be treated with radial interventional or endoscopic balloon dilation. Dumping syndrome: When patients eat high-sugar, hypertonic food, a large amount of hypertonic substances entering the intestinal lumen can cause a large amount of intestinal fluid secretion, causing patients to show signs of effective blood volume deficiency, such as abdominal distension and pain, profuse sweating and dizziness. Generally, no special treatment is needed, and it can be relieved by appropriately delaying the eating time and developing good eating habits. Intestinal obstruction: It can occur in the early postoperative period, mostly caused by postcolonic gastrojejunal anastomosis and intracolonic mesenteric foramen hernia formation, or it can be caused by late adhesions. Careful closure of the colonic mesenteric foramen can be avoided during surgery, and laparoscopic surgery can be adopted when conservative treatment is ineffective. Weight loss results: Standard 75 cm Roux-arm gastric bypass can usually reduce 65% to 70% of the overweight portion of the body weight and 35% of the preoperative BMI. Weight loss can plateau in 1 to 2 years, but there may be a rebound of about 10 kg or so after the lowest point of weight loss is reached. In 2000, Gagner et al. first performed LSG for severe obesity. For patients with very severe obesity and high-risk patients with other serious obesity complications, there is a high risk of performing complex weight loss surgery. LSG can be used as a relatively safe first-stage surgery for the initial surgical treatment of the first stage of patients with very severe obesity, and the decision of whether to perform the second stage surgery, such as LBPDDS or LRGB, will be made 6 to 18 months after surgery according to the weight loss. If the weight loss is satisfactory, stage 2 surgery may not be performed. If the result of weight loss is satisfactory, the second stage surgery may not be performed. Complications : Early and late complications of LSG are low, with an overall complication rate of 7.5% to 8.0%. Since gastrectomy is accomplished with a cutting closure, bleeding and leakage from the gastric incision margin are the most common surgical complications. Intraoperatively, sutures can be taken to reinforce the incision margin and a melan leakage test can be performed intraoperatively to prevent complications, depending on the situation. Weight loss results: This procedure is suitable for high-risk and extremely obese patients, who can lose 30% to 60% of the overweight portion of their body weight over 6 to 12 months. In 1980, Mason began performing LVBG, which is a simple and easy procedure to achieve weight loss without significant sequelae, but the patient is prone to vomiting, which has a greater impact on quality of life, and the patient is also prone to regain weight, which has been replaced by LRGB and LAGB in recent years. The reduction of preoperative BMI is 25% to 30%. LBPDDS is effective for obese patients, especially those with very severe obesity (BMI>60kg/m2), and has a long-lasting effect. The perioperative mortality rate is 1% and the complication rate is 5%. Long-term complications include dumping syndrome, diarrhea, vitamin, micronutrient, and nutrient deficiencies, especially protein. Daily supplementation of 75-80g of protein and vitamins and trace elements is required. LBPDDS can reduce approximately 70% of the overweight portion of the body weight and 35% of the preoperative BMI. Epidemiological surveys in China have found that the overweight population in China has reached 300 million and obesity is up to 50 million [10]. The results of the 2007 Beijing sample survey at Peking Union Medical College Hospital showed that the incidence of overweight and obesity in Beijing reached 36.4% and 13.5%, respectively, and a significant proportion of these patients required surgical treatment [11].Buchwald et al [12] showed that the cure rate of diabetes mellitus after weight loss surgery reached 76. 8%, with an improvement rate of 86%; the remission rate of hyperlipidemia exceeded 70%; and Hypertension had a cure rate of 61.7% and an improvement rate of 78. 5%. Surgical procedures can effectively control the number of obese population, reduce obesity associated diseases, improve the quality of life of obese patients and prolong life expectancy; therefore, weight reduction surgery will have a broad development prospect in China. At present, there is a lack of systematic and comprehensive obesity treatment system and standard in China, and it is a long way to go to formulate the surgical indications and treatment standard in accordance with Chinese conditions, improve the efficacy and reduce the complications, and improve the medical access system for obesity surgery.