The normal value of 2-hour postprandial blood glucose is less than 7.8mmol/L. Measuring blood glucose 2 hours after meal helps to determine the function of pancreatic B-cells to release insulin, i.e., to check whether the reserve function of pancreatic B-cells is normal or not. The normal standard of 2-hour postprandial blood glucose is less than 7.8mmol/L, the blood glucose concentration of 2-hour postprandial blood glucose examination in patients with impaired glucose tolerance is 7.8-11.0mmol/L, and the result of 2-hour postprandial blood glucose examination is greater than or equal to 11.1mmol/L to consider the possibility of diabetes mellitus. However, to diagnose diabetes mellitus, laboratory tests can not only through the 2-hour postprandial blood glucose test results, but also need to carry out fasting blood glucose and glycated hemoglobin test. Some patients may have normal 2-hour postprandial blood glucose but have abnormal fasting blood glucose and glycated hemoglobin results, which can also lead to a diagnosis of diabetes mellitus. If a patient’s two-hour postprandial blood glucose value is found to be above the normal range during a physical examination, he or she should immediately seek medical attention for additional laboratory tests such as fasting blood glucose, glycated hemoglobin and urine glucose measurement, and follow the doctor’s instructions for the treatment of diabetes mellitus, which can also be controlled by improving the structure of the diet, and should not be treated with medication on his or her own.