Immunotherapy strategies have shown benefits in the treatment of multiple myeloma (MM), however a certain percentage of patients progress to relapsed or refractory MM. In addition to monoclonal antibodies against antigens on tumor cells, the latest immunotherapy strategies include bispecific antibodies, immune checkpoint inhibitors, chimeric antigen receptor modified T cell and Bruton tyrosine kinase inhibitors, which provide more possibilities for immunotherapy of relapsed or refractory MM.