For ordinary diabetic patients, the standard of blood glucose two hours after meal is generally <10mmol/L. For gestational diabetic patients, the blood glucose two hours after meal is required to be less than 6.7mmol/L, and the standard can be appropriately relaxed for elderly patients. General diabetes mellitus two hours after meal blood glucose level can not be more than 10mmol / L, blood glucose level is too high may be too much diet or drug dose is insufficient, prolonged increase will increase the risk of cardiovascular and cerebrovascular disease. Pregnancy requires appropriately strict, less than 6.7mmol/L, too high blood glucose may not be conducive to the development of the fetus, and even increase the risk of pregnancy, but also pay attention to avoid the occurrence of hypoglycemia. Elderly diabetic patients, due to the many comorbidities and short life expectancy, can relax the level of blood glucose control appropriately, such as 2-hour postprandial blood glucose can be controlled at about 11-13.9mmol/L, in order to prevent hypoglycemia, which can induce cardiac infarction, cerebral infarction and so on. Diabetic patients should strengthen the monitoring of blood glucose in the course of treatment, and make appropriate adjustments to the drugs according to the blood glucose level, but under the guidance of endocrinologists to adjust the drugs.