Diabetes is known as “the cancer that won’t die”. Although it is scary, as long as you can control your blood sugar well, you can ensure that your body will not be tortured by the disease. Insulin injection is the main way to control blood sugar. Insulin injections are frequent, so you need to rotate the injection sites so that you can minimize the damage to your body. Wrong injection rotation technique will lead to repeated injury of the same injection site, coupled with the growth-promoting effect of insulin, the patient’s injection site will gradually appear “rubber-like” tissue, and when insulin is injected into the site again, the absorption of insulin will be delayed, reduced, and blood glucose fluctuations and hypoglycemia events will increase, while the daily insulin consumption and cost will also rise. The daily insulin consumption and cost will also increase. How can we rotate the injection sites to optimize the effectiveness of insulin? How can we rotate the injection sites so that insulin is most effective, while minimizing the important risk factor of subcutaneous fat gain? This requires a clear understanding of several parts of the diabetes injection, as well as the injection method and time: First, the abdomen is the preferred part of the diabetes injection site, insulin injection sites include the upper outer arm, abdomen, thighs, anterior and lateral thighs and buttocks outside the upper 1/4. The subcutaneous adipose tissue in these areas is favorable for insulin absorption, and the distribution of nerve endings is less, so the discomfort of injection is relatively less. The abdomen is the preferred site for insulin injection. Second, the injection site is divided into four aliquots, and one aliquot is used every week and always rotated in a clockwise direction; when injecting in any aliquot, the injection points should be spaced at least 1cm apart each time to avoid repeated tissue damage. Third, insulin different injection time is different, regular insulin needs to be injected before meals, the use of fast-acting insulin does not need to be injected in advance, but you must eat immediately after injection to avoid hypoglycemia. Short-acting insulin can be injected after meals as prescribed by the doctor. Medium- and long-acting insulin can keep blood glucose stable at night and avoid high blood glucose before dawn, and should be injected before bedtime. Fourth, the injection also needs to master the skills, insulin pen is an advanced injection device, widely used in clinical practice. In order to ensure that insulin is injected into the subcutaneous, if an 8 mm needle is used, the skin must be pinched and the skin fold must not be loosened prematurely. Failure to pinch the skin during injection may result in a risk of intramuscular injection. Injections need to be given quickly at 45°, injecting the drug slowly and then removing the needle. And if the patient is using a 5 mm needle, the needle should be inserted vertically without pinching the skin. Only by using the correct injection rotation technique can the development of lipoatrophy be avoided as much as possible and better glycemic control be obtained.