With the rapid development of China’s economy, obesity and diabetes have become serious social problems. According to the China Nutrition and Health Survey, there are more than 280 million overweight and obese people in China, which is close to 1/4 of the total population, including 68.44 million obese people. In addition, the prevalence of adult diabetes in China is 9.7%, about 92.4 million people, of which T2DM accounts for 90%, while the prevalence of pre-diabetes is 15.5%, all of which is the highest in the world. And 2013 statistics show that: the proportion of diabetes in China’s urban population is rising rapidly to 11.3%, which is an alarming figure. 1.Indications for obesity surgery Adult BMI is categorized as follows: (1) Healthy: 18.5-22.9 kg/m2, (2) Overweight: 23.0-24.9 kg/m2, (3) 1st-degree obesity: 25.0-29.9 kg/m2, (4) 2nd-degree obesity: 30.0-34.9 kg/m2, and (5) 3rd-degree obesity: >35.0 kg/m2. Chinese The guidelines for surgical treatment of obesity recommend that the key to surgical treatment of obesity – associated morbidity caused by simple fat excess (metabolic disorder syndrome) – be the indication for selecting patients for surgery, and that those who have one of the following (1) to (3), and at the same time have the following (4) to (7) conditions, may be considered for surgery: (1) Confirmation of the presence of metabolic disorder associated with simple fat excess (1) Confirmation of metabolic disorder syndromes related to excess fat alone, such as type 2 diabetes mellitus, cardiovascular disease, fatty liver, lipid metabolism disorders, sleep apnea syndrome, etc., and prediction that weight loss can be effectively treated. (2) Waist circumference: male ≥90 cm, female ≥80 cm; dyslipidemia; TG (triglyceride) ≥1.70 mmol/L and/or fasting blood HDL-C (high-density lipoprotein cholesterol): male <0.9 mmol/L, female <0.1 mmol/L. (3) Stable or steadily increasing body weight for more than 5 consecutive years, with a BMI ≥32 kg/m2 (which should refer to the patient's coefficient calculated from the weight with confirmed records under normal conditions and height at that time, while special circumstances such as within 2 years after pregnancy should not be used as the basis for selection). (4) Age 16-65 years old: for those above 65 years old, due to the stubborn and complicated complications related to obesity, the pros and cons of surgery should be weighed according to the preoperative examinations before deciding whether to operate or not; for adolescent patients under 16 years old, the degree of obesity, the impact on learning and life, as well as whether there is a family history of hereditary obesity or not, and whether the patient wishes to operate or not should be taken into consideration. (5) Those who have been treated poorly or cannot tolerate non-surgical treatment. (6) No alcohol or drug dependence, no serious mental disorder, intellectual disability. (7) The patient understands the bariatric surgery procedure, understands and accepts the risk of potential complications; understands the importance of postoperative lifestyle and dietary changes for postoperative recovery and has the ability to tolerate them, and is able to actively cooperate with the postoperative follow-up. On the contrary, surgical treatment is not recommended. 2.Indications for surgery for diabetes mellitus Surgery for diabetes mellitus is currently performed in various units in China not only for morbid obesity and BMI, but the nature of these surgeries should be regarded as purely as part of a pilot study pre-approved by the Ethics Committee only, and should not be widely promoted; patients with T2DM who are aged <60 years old or who have a better general health condition and a lower risk of surgery can be considered for surgical treatment. Regarding surgical treatment of diabetes mellitus; the duration of diabetes mellitus is mostly considered to be <10 years; the use of insulin use is mostly considered to be less than 10 years. (1) Our indications do not put BMI in a very important position, but rather metabolic disorder syndrome, fatty liver, hypertension, etc. as indications for surgery. (2) We put waist circumference and hyperlipidemia as a very important indicator, it is not necessary that the patient should be obese to a certain degree. (3) To calculate the BMI at the heaviest weight. (4) How to judge the effect of bariatric surgery: not to lose weight, if the weight change is not big, but hypertension, diabetes, hyperlipidemia relief, this is effective. There is sufficient information to show that surgery can treat diabetes and has better results, but the surgical mechanism and other things need to be further studied. For BMI>30 kg/m2 and above, surgical treatment is still more effective, but there is not much data on the effectiveness of treatment for those with BMI<30 kg/m2 and below.