According to the latest New England Journal of Medicine, China has 92 million diabetics and 140 million pre-diabetics, surpassing India as the country with the most diabetics in the world, and there are about 5 to 10 million patients with type 1 diabetes who need long-term insulin injection treatment. Although insulin injection can achieve the purpose of blood sugar control, islet transplantation is still considered as one of the effective treatment methods for type 1 diabetes, and the main sources of islets are 1. However, the main problems of human islet transplantation are the difficulty of source, the poor quality of pancreas, and the technique of isolation, which often requires more than one pancreas to be provided to a patient. 2.Pig islets: pig insulin differs from human insulin by one amino acid sequence and can perform normal functions, so pigs are considered to be the ideal source of islets at present. At present, clinical trials of porcine islets transplanted to human have been carried out both at home and abroad, and good results have been achieved. With the development of genetic process technology, the survival time of islets after transplantation will be further improved, and it may become the best method for treating type 1 diabetes in the future. 3, stem cells: stem cells can form islet cells in vitro or in vivo by the action of some specific inducers, but the technology is still immature and may lead to cell carcinogenesis, so the clinical application prospects are currently inferior to human islets and pig islets.