Insulin therapy is necessary for the treatment of type 1 diabetes, but it is also increasingly being used for type 2 diabetes, so what factors do doctors consider when enabling insulin therapy. 1. whether insulin therapy should be chosen 2. what type of insulin and insulin syringe should be chosen 3. whether the patient can master the insulin injection technique and site 4. for type 2 diabetes, the starting dose and duration of insulin therapy; 5. which oral medications can be combined with insulin 6. clearly informing the patient of the control goals of blood glucose and glycated hemoglobin after treatment; 7. the patient 7. Patients’ diet, lifestyle and work nature, and financial ability are also important reference factors in choosing insulin dosage and injection methods; 8.