The fastest absorbing part of topical insulin is the inner thigh muscle. The inner thigh muscle part of human body has more blood vessels and rapid blood circulation flow, which can effectively transport insulin from peripheral blood circulation into central blood circulation to relieve the symptoms of high blood sugar. The muscle nerves in the inner thigh of human body are more sensitive, and they also react more intensely to the painful sensation of needling, which can easily affect the effect and sensitivity of using insulin. Insulin injection in the inner thigh muscle can affect the half-life of insulin, which has a reverse effect on the whole course of medication. It is recommended to inject the skin of abdominal muscles or the skin of outer thigh muscles when using insulin, which can relieve the pain when insulin is injected into the needle and at the same time can strictly control the blood concentration to prevent hypoglycemia.