The percutaneous transhepatic portal approach is the most commonly used technique for islet transplantation, largely owing to its safety and minimally invasive characteristic. Bleeding complications after islet transplantation are rare. A case of type 1 diabetes mellitus (T1DM) was treated in Tianjin First Center Hospital, who had a massive intra-abdominal hemorrhage after percutaneous transhepatic portal vein catheterization for islet transplantation. Through the review of the overall development of the case, we aim to improve the awareness of the complications of islet transplantation, to reduce the incidence of complications after percutaneous transhepatic portal vein transplantation, and to provide experience.