It is generally recommended that insulin needles be replaced after one use. Insulin needles are disposable medical supplies and diabetic patients are very susceptible to infection. To avoid infection, it is generally recommended that insulin needles be replaced after one use. Repeated use of needles may not only cause infection, but may also lead to bending and deformation of the needle, and may even result in the needle being folded under the skin during the injection process. In addition, when injecting insulin, the injection site should be rotated to avoid the occurrence of subcutaneous fat atrophy, hyperplasia and other adverse reactions. Patients who need insulin injections should use them under the guidance of a doctor, and try to make the needles disposable.