Fatty liver disease (fatty liver) is a disorder of fat metabolism in the human liver, resulting in the accumulation of fat in the liver and exceeding 5% of the liver weight. The prevalence of alcoholic liver disease remains high, while the incidence of nonalcoholic fatty liver disease is increasing and tends to be younger. The prevalence of non-alcoholic fatty liver disease is 20-30% in developed countries such as Europe and the United States, and 12-24% in the Asia-Pacific region; in China, it is the second most common liver disease after viral hepatitis, with a prevalence of 12.6%-25% in adults and 2.1%-7.5% in children. It is noteworthy that it can not only coexist with viral hepatitis, but is potentially progressive, including three progressive pathological stages: fatty liver, steatohepatitis, and cirrhosis, whether due to obesity, type 2 diabetes, or alcoholism. Death may even occur as a result of liver failure and liver cancer. Non-alcoholic fatty liver disease is also closely associated with type 2 diabetes, atherosclerotic cardiovascular and cerebrovascular pathologies, and tumors associated with the metabolic syndrome. For this reason, fatty liver has become a new challenge in the field of contemporary liver disease, which poses a serious threat to human health and social development, and the effective prevention and treatment of fatty liver is expected to improve the prognosis of the majority of patients. The diagnosis of NAFLD has long lacked specific biochemical indicators for testing, and histopathological examination of the liver is the gold standard for diagnosis, but it is an invasive test that is difficult to perform routinely. Therefore, at present, the diagnosis of NAFLD and the determination of treatment efficacy must rely on imaging, with ultrasound still being the preferred means of examination, CT being suitable for diagnosis and assessment of treatment efficacy in specific patients, and MRS not yet entering the stage of practical clinical application. For alcoholic fatty liver, firstly, there should be a history of long-term alcohol consumption for more than 5 years, with an alcohol equivalent of ≥40g/d for men and ≥20g/d for women; or a history of heavy alcohol consumption within 2 weeks, with an alcohol equivalent of ≥80g/d; secondly, there should be typical manifestations of liver ultrasound or CT examination; in addition, hepatophilic virus infection, drugs and toxic liver injury should be excluded. The treatment strategy of fatty liver focuses on stopping the progression of the disease and actively eliminating the primary causes and triggering factors, such as obesity, diabetes, dyslipidemia and alcoholism. Specific measures include: 1. Strengthen health education, promote good lifestyle habits, low calorie, low fat, low salt diet, quit smoking and alcohol, and adhere to physical exercise. 2.Correct related risk factors to control weight, blood sugar, blood pressure and adjust blood lipids; 3.Avoid “second strike” to reduce the burden on the liver; 4.For those with abnormal liver function, metabolic syndrome, ineffective after 3-6 months of basic treatment, as well as those with liver biopsy confirmed as fatty liver and chronic progressive course of the disease, we can use specific medication for liver disease. The drug treatment for liver disease includes antioxidant, anti-inflammatory and anti-fibrotic drugs, such as polyphosphocholine, vitamin E, and silymarin, etc. Generally, 1-2 kinds of drugs are used for more than six months, or until the transaminases are normalized and the imaging examination indicates that the fatty liver has subsided. In conclusion, simple fatty liver is an early manifestation of liver injury, and if the cause is removed and the primary disease is controlled in a timely manner, the fatty deposits in the liver will completely subside within a few months. However, if the disease has progressed to the steatohepatitis stage, full recovery often takes half a year or even several years, and in a few patients, even if the cause is removed, it may still progress to cirrhosis. Therefore, it is very important to pay attention to fatty liver and enhance the early diagnosis and treatment of fatty liver.