Stem cells are primitive cells that have not yet differentiated. Stem cells have the ability to self-renew and differentiate into a variety of tissue cells, including bone cells, nerve cells, and cardiomyocytes. Stem cells can secrete a variety of cytokines and growth factors to improve the microenvironment of damaged tissues. More importantly, stem cells have the ability of immune tolerance and immunosuppression, thus limiting the inflammatory response of damaged tissues and facilitating the repair of damaged tissues. Hematopoietic stem cell transplantation is an effective treatment for malignant hematological diseases (leukemia, malignant lymphoma, multiple myeloma), aplastic anemia, and certain genetic diseases. In recent years, stem cell transplantation has been gradually applied in the treatment of mid- to late-stage malignant solid tumors (small cell lung cancer, breast cancer, ovarian cancer, testicular cancer, neuroblastoma, etc.), heart disease, neurological damage, tissue and organ repair, diabetes, vascular diseases, etc. In addition, stem cell transplantation has the ability to enhance the immunity of the body. In addition, stem cells have the potential to enhance human immunity, repair diseased or aging tissues, extend human life span, and change human existence, and thus have inestimable medical value. Stem cell technology is the most cutting-edge high technology in life science field today, and was listed as one of the “Top Ten Scientific and Technological Advances for Humanity” by the world’s most authoritative Science magazine for two consecutive years in 1999 and 2000. The maturity of stem cell related technology and clinical application has greatly promoted the development of regenerative medicine and foretold the bright future of stem cell technology industrialization.