Normally, we would do biochemistry testing of intravenous blood glucose in the hospital, because there are stricter procedures and quality control standards, so the results are relatively accurate. So the diagnosis of diabetes is based on intravenous blood glucose as the standard. Because the accuracy of blood glucose meter is affected by temperature, humidity and its own stability and sensitivity, the blood glucose value measured by it may be different from the venous plasma blood glucose value measured by biochemical meter. Therefore, the blood glucose measured by our portable blood glucose meter at home cannot be used as the basis for diagnosing diabetes. Since it is convenient and easy to use, it can monitor blood glucose at any time, so it is also one of the necessary tools for diabetic patients. As long as we pay attention to the monitoring method, it is not much different from the biochemical intravenous blood glucose. At present, the error range of most blood glucose meters has reached 10% or even lower, so it is completely possible to refer to the results of blood glucose meters to adjust the amount of medication and diet and exercise. Of course, we should also pay attention to the regular review of biochemical blood glucose and glycated hemoglobin monitoring.