Diabetes is a chronic metabolic disorder, which may lead to a series of serious complications and endanger human life in severe cases. Regular monitoring of blood sugar levels can help patients prevent diabetes complications. In this review, firstly, the causes and classification of diabetes, the background knowledge of non-invasive blood glucose monitoring, the classification of blood glucose monitoring methods, the basic theory of optical methods, and the process of non-invasive blood glucose monitoring are described. Then, the basic structure of the fiber laser, and the significant characteristics of the output light pulse are introduced. Most importantly, five optical methods that the fiber laser can be applied to non-invasive blood glucose monitoring are described in detail. Finally, this review describes the process of electrical signal processing in the non-invasive blood glucose monitoring device, some important algorithms, and the means of device performance evaluation.