Blood glucose less than 7.8mmol/L two hours after meal is normal. Two-hour postprandial blood glucose is generally calculated from the first meal after two hours of blood glucose concentration, after eating blood glucose will rise rapidly, the body will accordingly secrete insulin to antagonize the elevated blood glucose concentration, so the normal range of two-hour postprandial blood glucose should be less than 7.8mmol/L. If the blood glucose is in the range of 7.8~11.1mmol/L, it belongs to the abnormal glucose range of glucose tolerance. If the two-hour postprandial blood glucose is in the range of 7.8~11.1mmol/L, then it belongs to the glucose range of glucose tolerance abnormality, and if it is greater than 11.1mmol/L, then it has already reached the glucose standard for the diagnosis of diabetes mellitus. Patients with abnormal two-hour postprandial blood glucose should go to the hospital and ask their doctor to make a judgment.