The first choice for type 1 diabetes is insulin therapy. For patients with type 1 diabetes mellitus, auxiliary hypoglycemic therapy such as metformin can be added according to the blood glucose control situation when necessary, but attention should be paid to the age at which the drugs are applicable, and it is recommended that they be used jointly under the guidance of a specialist. Type 1 diabetes mellitus patients are mainly pancreatic β-cell secretion of insulin is obviously insufficient to meet the physiological needs, completely or partially need exogenous insulin replacement to maintain the balance of glucose metabolism in the body and survival. Therefore, insulin therapy is the preferred treatment option for type 1 diabetes. Patients with type 1 diabetes usually require a combination of oral medications on top of insulin, which can reduce insulin dosage and blood glucose fluctuations. For overweight or obese people with type 1 diabetes who have insulin resistance and increased insulin requirements, metformin (contraindicated in children under 10 years of age) can be combined if necessary. Insulin treatment of unsatisfactory blood glucose control, it is recommended to take under the guidance of professional doctors in regular hospitals, avoid unauthorized use of medication or adjust the dose. Pay attention to closely monitor blood glucose during treatment.