Insulin is a peptide hormone, and the amino acids in insulin will be denatured when they encounter iodine, which will affect the dose and efficacy of insulin. Therefore, iodine and iodophor should not be used when disinfecting the skin for insulin injection, and alcohol should be used. Subcutaneous insulin injection is a common method of blood glucose control for diabetic patients. The use of insulin must be under the guidance of a doctor, and the appropriate insulin treatment plan must be selected according to the patient’s blood glucose, age, type of diabetes and complications. Diabetic patients need to master the correct method of insulin injection and need to do the following when performing insulin injection: 1. Clean and disinfect the injection site well, use 75% alcohol when disinfecting the skin, and wait for the alcohol to dry before injecting to prevent aggravating the irritation of the injection site. 2. Subcutaneous insulin injection cannot be disinfected with iodophor or iodine, because the amino acids in insulin will Do not use alcohol to disinfect the injection needle, as alcohol will destroy the lubricating silicone oil on the needle and increase the pain during injection. 4. Stay under the skin for at least 10 seconds before pulling out the needle to prevent the insulin solution from spilling out.