Multiple myeloma (MM) is a malignant plasma cell disease that causes a large number of deaths every year. In the present study, we investigated the effect of bortezomib, the first-line drug for MM, on B cell maturation antigen (BCMA) of MM cells in order to obtain better efficacy of CAR-T therapy. Flow cytometry and ELISA analysis revealed that the bortezomib steadily increased BCMA expression level in the MM cell line Nalm6-BCMA, thereby enhancing the killing efficiency of CAR-T cells, while the increase of BCMA expression was sustained, allowing more time for CAR-T to effect. In addition, the combination of CAR-T and bortezomib has not yet been developed, suggesting that this combination therapeutic approach may hold great promise for the treatment of MM.