In this review, we discuss the application of microfluidic devices in studying the physiology and pathophysiology of human islets and beta-cells, especially its application for human islet transplantation. Human islet transplantation is a promising therapy for Type I diabetes; however, the islet transplant outcomes for achieving complete insulin independence are far from perfect and face many challenges. This review focuses on the microfluidic devices developed in our laboratory, which can address these challenges in the field of human islet transplantation, and briefly review the design and fabrication principles of these microfluidic devices and their main application.