Non-alcoholic fatty liver disease (NAFLD) is a metabolic stress liver injury closely related to insulin resistance and genetic susceptibility. Its pathological changes are similar to those of alcoholic liver disease, but patients do not have a history of excessive alcohol consumption, and the disease spectrum includes non-alcoholic simple fatty liver (NAFL), non-alcoholic steatohepatitis (NASH) and its associated cirrhosis and hepatocellular carcinoma. The prevalence of NAFL in obese patients ranges from 60% to 90%, NASH from 20% to 25%, and cirrhosis from 2% to 8%, while the prevalence of NAFLD in patients with type 2 diabetes and hyperlipidemia ranges from 28% to 55% and 27% to 92%, respectively. With the global epidemic of obesity and metabolic syndrome, the prevalence of NAFLD in Asian countries has been growing rapidly in the past 20 years with a trend of lower age prevalence, and the prevalence of adult NAFLD in developed areas such as Shanghai, Guangzhou and Hong Kong in China is around 15%. The rate of liver disease progression in NAFLD patients depends mainly on the histological type of the initial liver biopsy (liver biopsy for short).NAFL progression is slow and the incidence of cirrhosis is low (0.6%-3%) over 10-20 years of follow-up, whereas the incidence of cirrhosis in NASH patients is as high as 15%-25% over l0-15 years.The dangers of NAFLD not only promote the progression of liver disease, but also act as The study showed that the incidence of diabetes mellitus, hyperlipidemia, coronary heart disease and hypertension in patients with NAFLD is significantly higher, and some studies suggest that NAFLD is a contributing factor and a predictor of the development of these diseases.