In this paper, the separation, synthesis and biological activities of glycosylated iminosugars are systematically summarized. The naturally occurring glycosylated iminosugar products can be classified into five types according to their iminosugar units. Most of them have important biological activities, especially glycosidase inhibitory activities. Potential pharmacological activities of these compounds promote the study of synthetic strategies. According to the construction methods of glycoside bonds, these strategies can be roughly divided into enzyme catalyzed transglycosylation and chemical synthesis, of which the main difference is reaction condition. Enzyme catalyzed transglycosylation features mild reaction conditions and possible avoidance of protection groups, but the reaction efficiency and selectivity still need further improvement. Many synthetic strategies for ordinary glycosides can be used in chemical synthesis of glycosylated iminosugars, and are applicable for almost all synthetic targets. However, burdensome protection-deprotection procedures pull down the efficiency of chemical synthesis. The development of synthetic strategies have promoted the design and synthesis of the natural products and their analogues, which greatly enriches the variety and biological activities of glycosylated iminosugars. Generally, biological activities of glycosylated iminosugars are influenced by both the glycosyl groups and the iminosugar units. As the cross-domain of traditional carbohydrate chemistry and iminosugar chemistry, the structural diversity of glycosylated iminosugars provides excellent parent skeletons for the development of highly active and selective lead compounds, which endows these compounds with potential applications in drug discovery.