Abstract: Islet transplantation is a promising treatment of diabetes mellitus and its complications. Nevertheless, dysfunction post-transplantation, rejection and shortage of donors are the bottleneck issues in the field of islet transplantation. Optimizing the preservation method of pancreas plays a positive role in obtaining a sufficient quantity of effective islets and maintaining their functions. During the culture stage, anti-rejection and anti-apoptosis treatment of islets, including mesenchymal stem cell (MSC), MSC-derived exosomes, anti-apoptosis drugs and gene modification, may become major approaches for islet protection and functional maintenance in clinical islet transplantation. Use of anti-instant blood-mediated inflammatory reaction (IBMIR) drugs after islet transplantation also plays a critical role in protecting islet function. In this article, the whole process from islet preparation to islet transplantation was illustrated, and relevant strategies of islet protection and functional maintenance were reviewed, aiming to provide reference for improving the quality of donors to compensate for the shortage of absolute quantity of donors and elevating the efficiency of islet transplantation.