Microflow synthesis is characterized by rapid heating and cooling, precise temperature control, and efficient mixing, enabling reactions that are not feasible under conventional batch conditions (Fig. 31.1). Due to the ability to monitor reactions in real time, to precisely control reaction conditions, and to scale processes efficiently from laboratory to production scale, flow microreactor technology has been increasingly applied to the synthesis of pharmaceuticals and intermediates that demand high purity and production efficiency [1, 2]. Microflow-based glycan synthesis is being explored in both chemical [1–5] and enzymatic [3] approaches; however, most studies remain at the stage of basic research.