Diabetes is a major clinical and public health problem worldwide today, even in the preclinical period there is already a risk of vascular complications, and more than 50% of patients lack obvious symptoms and delayed examination and diagnosis, so it is important to conduct screening tests for early detection, early diagnosis and timely intervention and treatment for people at high risk of diabetes. The Chinese guidelines for the prevention and treatment of type 2 diabetes state that the following asymptomatic and undiagnosed groups should be screened for diabetes: 1. All obese people aged ≥45 years should be screened for diabetes, and if the screening test results are normal, a review should be done every 3 years. 2, the following cases should be in the younger population, or do more frequent screening: ① obese, refers to more than 20% of the ideal body weight or body mass index ≥ 25kg/m2 of the subject. ②People who have a history of diabetes in their first-degree relatives. ③People of high-risk race. ④Subjects who delivered a huge baby (birth weight ≥ 4 kg) or who had a history of gestational diabetes mellitus. ⑤ Those with a history of hypertension (blood pressure ≥ 140/90 mmHg). ⑥High-density lipoprotein cholesterol (HDL) ≤ 0.91 mmol/L and/or triglycerides ≥ 2.75 mmol/L. ⑦People with impaired glucose tolerance or abnormal fasting glucose in previous screening, cardiovascular and cerebrovascular diseases, sedentary lifestyle, etc.