It is well known that extracorporeal insulin injection has become an important tool in the treatment of diabetes. Whether it is type 1 diabetes patients who need to rely on exogenous insulin to maintain their lives or type 2 diabetes patients who are taking oral hypoglycemic drugs to control their blood sugar, the timely and appropriate application of insulin is very critical. However, in reality, we often see a lot of patients stopping insulin injections, or reducing or increasing the dosage for various reasons at will. Whether diabetic patients can self-adjust their insulin doses has become a common concern. In particular, some type 1 diabetic patients who have been injecting insulin for years believe that only the patients themselves are most familiar with their own condition and that it will be more beneficial to the smooth control of blood sugar if they can adjust the insulin dose according to their actual situation in a timely manner; however, almost every diabetic doctor will repeatedly explain that the adjustment must be made under the guidance of a professional physician, what is the reason for this? Dose adjustment of insulin seems to be a very simple thing: it’s just a matter of a few more units the day before and two less units today! In fact, insulin dose adjustment is a very complicated and professional issue, which involves a series of issues such as the type and dosage form of insulin chosen, insulin treatment method and blood glucose control goal, etc. Most diabetic patients have a partial understanding of these knowledge and do not master them systematically. First of all, there are many types of insulin, which can be divided into animal insulin (bovine insulin, porcine insulin), human insulin and insulin analogues according to their sources. According to the duration of action, it can be divided into ultra-short-acting insulin, short-acting insulin, medium-acting insulin and long-acting insulin, and other forms, in addition to various ratios of mixed insulins. Different insulins not only have different names, but also have different onset of action, peak and duration, and the dose regulation is different when different insulins are chosen. Secondly, there are various methods of insulin treatment: there are complementary treatment applied in combination with oral hypoglycemic drugs and alternative treatment with insulin completely. In the alternative treatment, there are conventional insulin treatment methods with premixed insulin injected twice a day and intensive treatment methods with short-acting and medium-acting (or long-acting) insulin injected three, four or even five times a day. Different methods, insulin dose adjustment is different, for example, with 30R of Novaline twice a day injection, if postprandial blood sugar is always poorly controlled, it may be related to its short-acting components, should consider changing to 50R of Novaline or adding oral hypoglycemic drugs to reduce postprandial blood sugar, such as Bystolic; and for example, with 4 times a day injection of intensive insulin therapy, fasting blood sugar is always poorly controlled, then For example, if the fasting blood glucose is not controlled by the intensive insulin therapy of 4 injections per day, it is necessary to take into account that there may be insufficient insulin dosage or the Sumuji phenomenon (hypoglycemia followed by hyperglycemia) or the dawn phenomenon and make different treatment, etc. Therefore, the adjustment of insulin dose and treatment method according to the condition can only be done by a professional physician. Furthermore, the adjustment of insulin dose is also related to the goal of blood glucose control, which in turn is related to the patient’s age, liver and kidney function, complications and comorbidities. If the patient is older and has poor tolerance to hypoglycemia, the blood glucose target value should be higher than that of general patients; or if the patient is combined with diabetic nephropathy and renal insufficiency, the patient is prone to hypoglycemia due to the reduction of insulin excretion, so the blood glucose target value should be relaxed; and if the patient is combined with pregnancy or gestational diabetes, the requirements for blood glucose are much stricter, not only the target blood glucose value should be relatively lower, but also the hypoglycemia should be avoided. In addition, it is necessary to avoid the occurrence of hypoglycemia. In addition, the dose adjustment of insulin should also take into account its adverse reactions. The most common adverse reaction is hypoglycemia, which can be manifested as hunger, pallor, sweating, palpitation, weakness, anxiety, etc. In the process of dose adjustment, the clinical manifestations of hypoglycemia can be different for different individuals and different conditions, and when hypoglycemia occurs, some patients do not take corresponding measures due to lack of awareness, which can lead to serious consequences such as coma Even death. Other adverse reactions such as allergy, edema, etc. Allergy can be manifested as rash, itching, shortness of breath, dizziness, etc. In serious cases, shock and coma can occur, and the patients themselves often cannot make correct judgments and miss the disease, while for some patients with heart failure, edema can aggravate heart failure, etc. All the above cases need to rely on professional physicians to make appropriate diagnosis and timely treatment to avoid the occurrence of danger. In conclusion, insulin dosage adjustment involves a variety of factors, even if the patient knows his condition very well, he cannot replace the professional physician to adjust the dosage. The correct method is that the patient can assist the physician to adjust the insulin dosage by strengthening the self-test of blood glucose and recording the changes of blood glucose, so that the blood glucose can reach a satisfactory control target, thus reducing or delaying the occurrence of chronic complications of diabetes.