Stem cell therapy for type 1 diabetes offers hope for the eradication of diabetes. The main options for stem cell transplantation include: 1) drug stimulation of stem cell mobilization and freezing of the patient’s bone marrow stem cells from the blood. 2) high dose chemotherapy for several days to destroy the diseased immune system. 3) infusion of the extracted stem cells back into the patient to establish a new immune system that does not attack the beta cells. Nowadays, the main types of stem cells include liver stem cells, spleen stem cells, small intestine stem cells, skin stem cells, umbilical cord blood stem cells, allogeneic stem cells and genetically engineered stem cells, etc. Stem cell treatment may also bring some complications, and the narrowly defined complications refer to the chronic complications of diabetes, including two major categories of vascular and neurological lesions.