Currently, insulin has become one of the very effective means to control hyperglycemia in diabetic patients, especially insulin intensive therapy, which can bring down hyperglycemia in a very short period of time, timely release the toxic effect of hyperglycemia and restore the function of pancreatic islet cells. Diabetic patients can be asymptomatic when hyperglycemia occurs, and the body can compensate for the correction when hypoglycemia occurs, and they do not necessarily show panic, sweating, hand trembling, etc. How can we keep blood sugar normal and prevent hypoglycemia effectively? First of all, to prevent hypoglycemia, we must check blood sugar regularly. Only by monitoring blood sugar more often can we understand the fluctuation of blood sugar. Patients with blood sugar below 4.4mmol/L before breakfast should be alert to the possibility of nighttime hypoglycemia. Increase monitoring of blood glucose level at night, and patients with better conditions can be hospitalized for 24-hour ambulatory blood glucose monitoring to detect hypoglycemia without conscious symptoms. Only by monitoring blood glucose frequently can we find out the high and low blood glucose levels, so that we can take effective measures for the changes of blood glucose at different times. Secondly, because the short-acting preparation of human insulin has a longer and slower action time than the ultra-short-acting insulin, and the medium-acting preparation has a potential absorption peak, the treatment of human insulin premixed preparation is prone to hypoglycemia before Chinese meals and at night, and the postprandial hyperglycemia control is unsatisfactory, and some people are prone to hypoglycemia at night because of the longer action time and potential absorption peak of the medium-acting insulin. In the early morning, hypoglycemia may occur. Therefore, for those who develop postprandial hyperglycemia or nocturnal hypoglycemia after the application of premixed insulin, it is necessary to replace premixed insulin with premixed insulin analogues in a timely manner because the short-acting formulations of premixed insulin analogues act quickly and for a short period of time and have a lower chance of hypoglycemia. Finally, the five horses of diet, exercise, gaining knowledge about diabetes, regular blood glucose monitoring, and regular medication should go hand in hand, and medication should be based on diet and exercise therapy. Because diet and exercise are the foundation of diabetes treatment, only when the foundation is firmly established, medication can be safe and effective. Therefore, if the diet and exercise regimen is reasonable, once hypoglycemia occurs, it is better to adjust the medication regimen rather than changing the diet and exercise.