The diabetic dawn phenomenon is bad because it is not conducive to blood glucose control. Dawn phenomenon is also known as good control of blood glucose at night, and there is no hypoglycemia phenomenon, only in the dawn of the transient hyperglycemia, may be due to the early morning free cortisol, growth hormone and other excessive secretion. If the diabetic dawn phenomenon persists and is not controlled in time, it will easily lead to various complications in diabetic patients, such as diabetic nephropathy and diabetic retinopathy. When diabetic dawn phenomenon occurs, we must pay attention to it, go to the regular hospital for examination and treatment as soon as possible, cooperate with the doctor to detect the changes in blood glucose level, and try to control the blood glucose in a reasonable range.