• Fully understand and voluntarily sign the informed consent form, and be willing and able to comply with the visits, treatment plans, laboratory inspections, and other requirements of the research as specified in the test procedure;

• Patients with relapsed/refractory plasma cell tumors determined by clinical diagnosis;

• The definition of relapsed/refractory plasma cell tumors is:

⁃ Primary resistance to standard treatment regimens;

⁃ Or PD occurs after standard treatment with at least second-line standard treatment plan;

⁃ Or the last treatment effect is SD and the duration does not exceed 6 months;

⁃ Or treatment with proteasome inhibitors and immunomodulators is ineffective or relapses;

⁃ Patients who have PD after autologous hematopoietic stem cell transplantation or confirmed recurrence by biopsy within 12 months, or patients who undergo salvage treatment after autologous hematopoietic stem cell transplantation have no remission or relapse after treatment.

• According to RECIST version 1.1 , there should be at least one measurable tumor (soft tissue mass) or serum M protein ≥10g/L or urine M protein ≥200mg/24h;

• Subjects whose physical status scored by the Eastern Cooperative Oncology Group (ECOG) is 0\

‣ 2;

• 14 years old ≤ age ≤ 75 years old, both male and female;

• Immunohistochemistry or flow cytometry detects tumor cells as BCMA or CD19/CD22/CD79 positive;

• The estimated survival period from the date of signing the informed consent form is greater than 3 months;

• Laboratory examinations meet the following conditions: hemoglobin ≥80g/L, platelet count ≥50 × 109/L, absolute neutrophil count (ANC) ≥1.0 × 109/L, if the investigator believes that the above inspection value is below the lower limit It is caused by tumor invading bone marrow and can be included in the group after consultation with the sponsor;

• The main organ function indicators meet the following conditions: AST (aspartate aminotransferase)/ALT (alanine aminotransferase)/ALP (alkaline phosphatase) ≤2.5 ULN, serum creatinine ≤1.5 ULN, total bilirubin ≤1.5 ULN, left Ventricular ejection fraction (LVEF) ≥50%, and minimum pulmonary function reserve (dyspnea is not higher than grade 1 and blood oxygen saturation\> 92% under indoor conditions).