Multiple myeloma, a malignant disease characterized by a massive proliferation of monoclonal plasma cells in the bone marrow. The treatment of multiple myeloma is mainly the application of systemic chemotherapy, which, after conventional chemotherapy, does not improve the survival time of patients, with a median survival of about 3 years. However, with hematopoietic stem cell transplantation, it can lead to a significant improvement in the survival rate of the patients, from 29% to 35% at 5 years and from 11% to 17% at 10 years. But most of the benefit is in younger patients. In recent years, with the use of some new drugs, such as bortezomib and lenalidomide, as well as improved methods of hematopoietic stem cell transplantation, the median survival of newly diagnosed patients with multiple myeloma has increased from the previous 30 months to 45 months; and for patients with relapsed disease, the median survival has also increased from 12 months to 24 months.