There is no most accurate time to measure blood glucose, and the level of blood glucose measured at different times is different. Blood glucose can be divided into fasting blood glucose, pre-meal blood glucose, 2h post-meal blood glucose and random blood glucose. The measurement time of each kind of blood glucose is as follows: 1. Fasting blood glucose: it is recommended to fast >8h, do not eat after 8pm, and check fasting blood glucose around 7-8am the next day, generally the fasting blood glucose value is 3.9-6.1mmol/L; 2. Pre-meal blood glucose: the blood glucose measured before eating; 3. 2h post-meal blood glucose: it is the blood glucose measured 2h after three meals from the first bite of meal. Post-meal 2h blood glucose <7.8mmol/L; 4. Random blood glucose: refers to the blood glucose measured at random time, such as before bedtime, early morning, etc., generally to <11.1mmol/L. In general, fasting blood glucose and post-meal 2h blood glucose can be monitored and detected, and diabetic patients should monitor the range of fasting blood glucose, post-meal 2h blood glucose, before bedtime, early morning and other 8 times blood glucose fluctuations in the first two weeks of dose adjustment, in order to regulate the drug dose, etc. It can be tested with fingertip blood, which is convenient and easy to operate, and can be tested by yourself. It should be noted that the blood glucose test paper should not expire, and at the same time, in the process of testing, do not squeeze the blood of the finger hard to avoid causing tissue fluid in the blood drops, which will cause inaccuracy of the test, and also try to avoid using the first drop of blood to test blood glucose.