In recent years, the incidence of diabetes in children and adolescents in China, especially in younger children, has increased significantly. Among them, type 1 diabetes is still predominant, accounting for 90%. Globally, the incidence of type 1 diabetes in children and adolescents in China is in the low incidence zone. However, because of the large population base in China, the absolute number of type 1 diabetes patients is not less than 1 million. However, not all children and adolescents with diabetes are type 1 diabetic. In recent years, improvements in the quality of life have led to a significant increase in childhood obesity, accompanied by an upward trend in type 2 diabetes. Also obesity is not uncommon in patients with type 1 diabetes, and sometimes type 1 and type 2 in children and adolescents with diabetes are not easily distinguished. There is also the possibility of confusion with MODY (adult-onset diabetes mellitus in adolescents). The diagnostic criteria for type 2 diabetes in children and adolescents are the same as those for adults, and children with type 2 diabetes usually have a family history, are obese, have an insidious onset, have few symptoms, do not require insulin therapy, or have acanthosis nigricans, hypertension, dyslipidemia, PCOS, or fatty liver. The overall goal of the treatment of type 2 diabetes in children and adolescents is to achieve a standard weight through dietary control and physical exercise, so that blood glucose is at a normal level, while improving metabolic disorders such as hypertension, hyperlipidemia, and nonalcoholic fatty liver, and preventing and delaying the occurrence of chronic complications. The goal of blood glucose control: fasting blood glucose <7.0mmol/L and glycated hemoglobin below 6.5% as much as possible. The treatment of type 2 diabetes in children and adolescents still requires a five-pronged approach. 1. Health education Not only health and psychological education for children with diabetes, but also knowledge related to diabetes for family members of children with diabetes is needed. 2.Diet control Considering the growth and development of children, diet control is based on the principles of maintaining body weight, correcting metabolic disorders that have occurred and reducing the burden on pancreatic β-cells. 900-1200kcal/d for children aged 6-12 years old and 1200kcal/d or more for 13-18 years old. Ratio of three nutrients: 45-60% carbohydrate, 25-30% fat, 15-20% protein. 3.Exercise therapy Insist on exercising at least 30 minutes a day and at least 150 minutes a week. 4.Pharmacological treatment (1) When lifestyle intervention cannot control blood sugar well, it is necessary to start pharmacological treatment. It can be metformin or insulin alone, or both in combination. Basal insulin or mealtime insulin therapy is used according to the situation. (2) Metformin starts at 500mg/d and increases by 500mg per week to 1000mg for 3-4 weeks, 2 days this. (3) Insulin therapy can be done with NPH or basal insulin once a day (starting dose 0.25-0.5u/kg). (4) If severe hyperglycemia, ketosis/ketoacidosis is present then insulin therapy is used. (5) There are not enough studies to prove that other oral hypoglycemic agents can be used in children. 5. Blood glucose monitoring Frequency can be individualized according to blood glucose control. Glycated hemoglobin should be measured at least twice a year, or every 3 months if treated with insulin or if blood glucose control is not up to standard.