Surgical bariatric procedures include two major categories of procedures: intake restriction and malabsorption. After half a century of development, bariatric surgery has been continuously improved by surgeons. Currently, the most used procedures include adjustable gastric banding, Roux-en-Y gastric bypass, sleeve gastrectomy and biliopancreatic diversion, all of which can be done laparoscopically. There has been a gradual recognition of bariatric surgery for the treatment of obesity combined with nonalcoholic fatty liver disease. From the 1950s to the 1970s, surgical weight loss surgery was mainly represented by jejuno-ileal short-circuiting, which was effective in weight loss, but had more postoperative complications such as malnutrition, metabolic disorders and liver fibrosis. There are reports of acute steatohepatitis and liver failure in some severely obese patients during rapid weight loss. The mechanism of their liver damage is not fully understood, and the main reason is considered to be the result of extensive fat metabolism leading to excessive free fatty acids that increase the metabolic burden on the liver and the occurrence of metabolic stress leading to acute steatohepatitis and liver failure. Despite the elimination of jejuno-ileal short-circuiting, there are reports in the literature of varying degrees of liver damage during rapid weight loss in severely obese patients after malabsorption-based bariatric surgery such as gastric short-circuiting, and biliopancreatic open-heart surgery with duodenal transposition, manifested as exacerbation of nonalcoholic fatty liver and subacute steatohepatitis. In recent years, some literature reported that obese patients after various weight loss surgeries improved or cured type 2 diabetes while losing most of their excess weight, and nonalcoholic fatty liver was significantly improved, as shown by improved liver function indexes and improved hepatitis degree and liver fibrosis on liver biopsy. Our experience is that about 85% of obese patients combined with non-alcoholic fatty liver disease, after laparoscopic vertical gastric banding, laparoscopic adjustable gastric banding, laparoscopic sleeve gastric reduction, laparoscopic Roux-en-Y gastric bypass, laparoscopic mini-gastric bypass and other procedures, the effect of weight loss in patients in the medium and long term is obvious. The majority of patients with type 2 diabetes are cured or improved, and most patients with non-alcoholic fatty liver disease are cured or significantly improved. Long-term clinical observation and follow-up are needed for the treatment of obesity metabolic syndrome and nonalcoholic fatty liver disease after bariatric surgery.