Multiple myeloma (MM) is a prevalent hematological malignancy. Despite the availability of various therapeutic agents, disease relapse remains inevitable. In recent years, B cell maturation antigen (BCMA)?targeted chimeric antigen receptor T (CAR?T) cell therapy has demonstrated remarkable success in treating relapsed/refractory (R/R) MM, offering new hope for RRMM patients. Currently, four types of BCMA?CAR?T products are available on the global market, and their application in RRMM is becoming increasingly widespread. However, RRMM patients who receive BCMA?CAR?T treatment still exhibit a high relapse rate. Research on maintenance therapy following BCMA?CAR?T treatment is currently limited, and multiple strategies exist for managing post?relapse RRMM after BCMA?CAR?T therapy.