Nonalcoholic fatty liver is a clinicopathologic syndrome characterized by fatty degeneration and fat accumulation in hepatic parenchymal cells without a history of excessive alcohol consumption. The disease spectrum varies with the progression of the disease and includes simple fatty liver, steatohepatitis, fatty liver fibrosis and cirrhosis. The clinical diagnostic criteria for nonalcoholic fatty liver can be diagnosed if any of the following items 1 to 5 and 6 or 7 are present 1, there are susceptibility factors such as obesity, type 2 diabetes, hyperlipidemia, etc.; 2, no history of alcohol consumption or the amount of alcohol equivalent <40g per week; 3, except viral hepatitis, drug-related liver disease, Wilson's disease, total parenteral nutrition and autoimmune liver disease; 4, in addition to the clinical manifestations of the primary disease, symptoms such as weakness, vague pain in the liver area, may be accompanied by hepatosplenomegaly; 5, serum transaminases may be elevated, and the 5.Serum aminotransferases may be elevated, with ALT as the main cause, and may be accompanied by increased GGT, ferritin and uric acid; 6.Hepatic histology has typical manifestations; 7.There is a basis for imaging diagnosis.