Non-alcoholic fatty liver disease (NAFLD) is a clinicopathological syndrome with diffuse hepatocellular steatosis, including simple fatty liver and the evolution of steatohepatitis (NASH) and cirrhosis, resulting from the accumulation of fat in the liver, excluding alcohol and other definite hepatoprotective factors. It is a genetic2environmental2metabolic2stress-related disease. The diagnosis of NAFLD can be diagnosed by having any of the following items 1-5 and 6 or 7: ①No history of alcohol consumption or alcohol consumption < 140 g per week in men and < 70 g per week in women; ②Excluding viral hepatitis, drug-related liver disease, total parenteral nutrition, hepatomegaly and other specific diseases that can lead to fatty liver; ③In addition to the primary disease, there may be a lack of clinical manifestations of fatty liver. (3) In addition to the clinical manifestations of the primary disease, there may be non-specific symptoms and signs such as fatigue, dyspepsia, vague pain in the liver area, hepatosplenomegaly, etc.; (4) There may be overweight and/or visceral obesity, increased fasting glucose, dyslipidemia, hypertension, and other components related to the metabolic syndrome; (5) There may be mild to moderate increases in serum aminotransferase and γ2 glutamyl transfer (GGT) levels (<5 times the upper limit of normal), usually with an increase in alanine aminotransferase (AL T). (6) Liver imaging is in accordance with the diagnostic imaging criteria of diffuse fatty liver; (7) Histological changes in liver biopsy are in accordance with the pathological diagnostic criteria of fatty liver disease. 2. Classification of NAFLD ① Non-alcoholic simple fatty liver ② Non-alcoholic steatohepatitis (NASH) ③ NASH-related cirrhosis 2. NAFLD is closely related to metabolic syndrome: insulin resistance is the basis of the pathogenesis of NAFLD. Definition of metabolic syndrome (IDF): a variety of metabolic disorders and related diseases co-exist with insulin resistance as a common pathogenic basis. Metabolic syndrome content: obesity/overweight, hyperinsulinemia, impaired glucose tolerance, hyperlipidemia, hypertension, platelet regulatory insufficiency, endothelial insufficiency, gout, iron overload, osteoporosis, polycystic ovaries, acanthosis nigricans, neuroendocrine abnormalities (anxiety, depression, abnormal appetite), etc. Diagnostic criteria for metabolic syndrome: 3 or more of the following indicators: 1, overweight or obesity: abdominal obesity: abdominal circumference >90 cm (men), >80 cm (women), and/or BMI ≥25 kg/m2 (regardless of gender); 2, dyslipidemia: fasting total cholesterol TG ≥150 mg/dl (1.70 mmol/L); and/or fasting blood HDL -C: <35 mg/dl (0.9 mmol/L) in men and <39 mg/dl (1.0 mmol/L) in women; 3, increased blood pressure: systolic/diastolic blood pressure ≥140/90 mmHg, and/or diagnosed and treated hypertension; 4, increased fasting blood glucose: FPG ≥6.1 mmol/L and/or OGTT ≥7.8 mmol/L. 7.8 mmol/L, and/or diagnosed and treated for diabetes mellitus. Treatment of NAFLD: 1. Basic treatment: treatment of concomitant diseases/related risk factors, basic treatment (behavioral therapy, dietary modification, exercise); 1) correction of poor lifestyle, abstinence from smoking, alcohol, overeating, etc.; 2) diet therapy is to adhere to reasonable balanced dietary habits, appropriate control of caloric intake, to reach the standard weight range; 3) appropriate aerobic exercise should be performed frequently in general. 2.Adjunctive drug therapy: treatment goal: to prevent and control the occurrence of inflammation, necrosis and liver fibrosis in the liver. At the same time of basic treatment, liver-protective and fat metabolizing drugs can be taken. When liver function abnormalities and liver fibrosis occur, adjuvant drug treatment should be given, which can be based on liver function test results: such as silymarin, ezetimibe, ursodeoxycholic acid tablets, etc. 3.End-stage treatment: liver transplantation