Non-invasive blood glucose monitoring will be the development direction for detecting the blood glucose concentration of body in time. In this way, the concentration of the blood glucose can be controlled effectively, then the complicating diseases of diabetes can be reduced, so it is of great significance for diagnosis and treatment of diabetes. The recent developments of non-invasive blood glucose concentration monitoring technologies, including basic principles, results of verification test and instruments, are discussed, especially three methods with instruments facing market. The existing problems of these methods are also discussed. Finally, some difficult points of current non-invasive blood glucose monitoring methods are further discussed and the future trend of the technologies has been pointed out according to the above analysis.