Diabetes is divided into type 1 diabetes, type 2 diabetes and gestational diabetes, and although they are all the same, the standards for glycemic control are very different. Even for the same type 2 diabetes, the goals of glycemic control are different for different conditions. The glycemic control standards for different categories of type 2 diabetic patients: 1. Young and middle-aged diabetic patients with short disease duration and no obvious cardiovascular disease Control standards: fasting blood sugar 4.4-6.1mmol/L, postprandial blood sugar <7.8mmol/L, HbA1c <6.5%, try to make HbA1c <6.0%. 2.Non-critical patients treated with insulin Control standard: Pre-meal glucose should be <7.8mmol/L and random glucose <10.0mmol/L, HbA1c<7.0% as far as possible. 3. Patients with mild condition, who can achieve the standard of blood glucose control without hypoglycemia through diet, exercise and taking hypoglycemic drugs (such as metformin, glycosidase inhibition, thiazolidinedione derivatives, etc.) and other treatment methods. Control standard: These patients should have normal or near normal blood sugar as far as possible. That is, fasting blood sugar 4.4-6.1mmol/L, postprandial blood sugar <7.8mmol/L. 4. Elderly patients aged 70-80 years old Control standard: Under the premise of safety, fasting blood sugar 6.0-7.0mmol/L, postprandial 2 hours blood sugar 8.0-10.0mmol/L, HbA1c between 6.5% and 7.0%. 5, combined with serious complications, especially combined with cardiovascular and cerebrovascular disease, or frequent hypoglycemia control standards: blood glucose control target should be relatively relaxed, generally fasting blood glucose maintained at 7.0 ~ 9.0mmol/L, postprandial blood glucose at 8.0 ~ 11.0mmol/L, HbAlc at 7.0% ~ 7.5% can be. 6. Patients with frequent hypoglycemia, older age or longer disease duration Control standard: fasting blood sugar 7.0~9.0mmol/L, 2 hours after meal blood sugar 8.0~11.1mmol/L, HbA1c in 7.0%~7.5%.