Fasting blood glucose should be controlled below 8.0 mmol/L before surgery. Long-term poorly controlled blood glucose in diabetes can lead to a variety of acute and chronic complications, and can also increase the rate of infection in patients after surgery and affect the healing rate of surgical incisions, or even cause non-healing. Therefore, diabetic patients should pay attention to good blood glucose control before surgery. The standard of blood sugar control before surgery is divided into the following categories according to the type of surgery: 1. Ordinary elective surgery requires fasting blood sugar control below 8.0mmol/L, and non-fasting blood sugar below 10.0mmol/L can be treated surgically. 2. Emergency surgery with random blood sugar less than 13.9mmol/L can be considered for surgery. 3. Fine surgery, such as plastic surgery and eye surgery, etc. Fasting blood sugar should be controlled below 7.0mmol/L and non-fasting blood sugar below 8.0mmol/L before surgical treatment can be performed. 4.Prohibited surgery, if diabetes combined with acute complications such as diabetic ketosis, diabetic ketoacidosis and hyperosmolar coma, surgical treatment should be prohibited. So diabetic patients who need surgical treatment, if oral hypoglycemic drug treatment cannot effectively achieve the goal of blood sugar control, they need to use insulin treatment or even insulin pump intensive treatment.