Dawn phenomenon is a phenomenon in which diabetic patients have stable blood glucose control at night, but their blood glucose rises in the early morning. Dawn phenomenon is a phenomenon in which blood glucose control is stable at night and there is no hypoglycemia, but in the early morning at 3-9 am, i.e. at dawn, there is an increase in blood glucose due to the imbalance of various hormone secretions in the body. Dawn phenomenon needs to be distinguished from Sumuje reaction, which is caused by hypoglycemia at night and rebound blood glucose increase in the early morning; diabetic patients with dawn phenomenon can use insulin pumps, injection of long-acting insulin or oral long-acting agonists to alleviate the situation. Patients with dawn phenomenon are advised to go to the hospital for consultation and treatment under the guidance of the doctor.