Non-alcoholic fatty liver disease is a broad spectrum fatty liver disease characterized by the progression from simple hepatic steatosis to non-alcoholic steatohepatitis and the eventual progression to cirrhosis in some patients, in addition to viral hepatitis, drug-related liver disease, autoimmune liver disease and hereditary liver disease, among people who do not drink alcohol or rarely drink alcohol. Nonalcoholic fatty liver is not only a liver lesion, but also, as an important organ for substance metabolism in the body, the liver is hazardous to human health because of its serious and extensive effects on blood glucose and lipid metabolism after the occurrence of fatty deposits. Because of the close relationship between fatty liver and glucose metabolism, fatty liver as a risk factor for diabetes is receiving increasing attention. The prevalence of NAFLD is increasing in parallel with obesity and type 2 diabetes, indicating that obesity plays a key role in the formation and development of NAFLD. Among obese patients, simple hepatic steatosis reaches 60% and steatohepatitis reaches 20-25%. fatty liver is present in about 80% of type 2 diabetic patients. The risk of cardiovascular diseases such as glucose metabolism, hypertension, lipid metabolism disorders, coronary heart disease and stroke is significantly higher in patients with fatty liver. Foreign reports show that about 50% of the population with non-alcoholic fatty liver has different degrees of abnormal glucose metabolism; research data from the endocrinology department of our hospital show that the incidence of abnormal glucose metabolism among patients with non-alcoholic fatty liver in Shanghai is as high as nearly 50%, with 35.2% of patients with pre-diabetes and 14.5% of newly diagnosed type 2 diabetes. Patients with fatty liver in the normal stage of glucose metabolism are more likely to develop type 2 diabetes and cardiovascular disease than those without fatty liver. Therefore, the prevention and treatment of NAFLD is of greater importance for early diagnosis and active prevention and treatment of type 2 diabetes and and cardiovascular disease, far more than treating the liver itself. With the popularity of medical checkups, the number of patients with fatty liver diagnosed through ultrasound is increasing. Due to the lack of specific symptoms and the lack of pain, many patients do not pay much attention to fatty liver, so that some patients come to the clinic only when they have persistent liver function abnormalities and progress to steatohepatitis, at which time the concomitant rate of abnormal glucose metabolism and cardiovascular and cerebrovascular disease risk is greatly increased. Once the diagnosis of fatty liver is made, the patient should be seen in a relevant hospital specialty. The causes of fatty liver should be clearly identified, such as differentiation from various types of viral hepatitis, autoimmune hepatitis, liver damage caused by drugs and toxins, and alcoholic liver disease. The extent of the damage caused by fatty liver and whether it is accompanied by steatohepatitis or cirrhosis are then determined by liver function. Not to be overlooked is the need to further clarify the presence of concomitant abnormal glucose metabolism or diabetes mellitus, hypertension, coronary artery disease, and abnormal lipid metabolism to assess the risk of diabetes and cardiovascular pathology. For patients with fatty liver whose glucose metabolism is still in a normal stage an oral glucose tolerance test is required to measure fasting and postprandial glucose. After these comprehensive assessments, a proper treatment plan can be formulated. Since ultrasound cannot accurately quantify liver fat content or classify the severity of fatty liver, liver fat can be accurately quantified, graded and staged by liver puncture pathology when the condition requires it. Fatty liver can be prevented and treated. The principles of prevention and treatment are: early detection, standardized diagnosis, comprehensive treatment, and the importance of persistence and prevention. Doctors and dietitians develop appropriate nutrition and exercise prescriptions and individualized comprehensive treatment plans according to individual conditions. The main goal of comprehensive treatment is to reduce weight, which can be reversed in early stage patients. The main approach to comprehensive treatment is to improve lifestyle, diet control and exercise are the basis and important means of treatment. It is important to remember that losing weight too fast can easily aggravate fatty liver, so it is important to follow the doctor’s instructions. For patients whose lifestyle treatment is still not satisfactorily controlled, medication can be reasonably chosen under the guidance of a physician, but medication must be accompanied by adherence to a diet and exercise regimen and perseverance to achieve a long-term cure.