CD38 is also expressed in a variety of hematological malignancies, including multiple myeloma. In the present invention, the inventors have obtained a novel antibody against CD38, which can be suitable for the production of bispecific antibodies as well as CAR-T cell populations. In particular, the inventors report the development of Bi38-3, which is a novel bispecific T cell binding agent that targets CD38 on MM cells and establishes cytotoxic T cells through CD3 epsilon. The Bi38-3 lacks the Fc region of the natural mAb, while the Fc region contributes to the resistance process, but elicits T cell proliferation, release of cytokines and lysis of CD38 positive MM cells in vitro. Similarly, Bi38-3 induces autologous T cells to eliminate tumor plasma cells isolated from MM patients at the time of diagnosis and recurrence. The cytotoxicity caused by Bi38-3 is only limited to cells expressing high-level CD38, and the integrity of T, B and NK lymphocytes is maintained in vitro. More importantly, the Bi38-3 can be used for rapidly reducing tumor cells in an MM1. S xenotransplantation mouse model of human MM. In conclusion, the result shows that the antibody is an effective reagent for specifically removing CD38 positive malignant cells, does not obviously influence CD38 low-expression cells, and is a novel immunotherapy tool expected to treat hematological malignancies, especially multiple myeloma.