• Subjects volunteer to participate in clinical trails, understand and inform the trials and sign informed consent form, be willing to complete all the trial procedures;

• 18 to 75 years old (including cut-off value)，gender is not limited;

• Expected survival \> 12 weeks;

• Previously diagnosed as multiple myeloma by the International Myeloma Working Group（IMWG） updated criteria;

• One of the following indicators is satisfied:

‣ Serum M protein ≥ 5 g/L;

⁃ Urine M protein ≥ 200 mg/24h;

⁃ Affected serum free light chain ≥ 100 mg/L and Serum free light chain ratio is abnormal ;

• Patients with relapsed/refractory multiple myeloma, satisfying:

‣ Patients have received at least 3 prior MM treatment regimens containing at least one proteasome inhibitor and one immunomodulator;

⁃ Progress is documented within 12 months of the most recent antimyeloma treatment, or efficacy assessment does not reach minimal response(MR) or above or progression within 60 days of the most recent antimyeloma treatment;

• ECOG score 0-2;

• Autologous hematopoietic stem cell transplantation is not possible or relapses after autologous hematopoietic stem cell transplantation, but requires further treatment at the investigator's discretion；

• Liver, kidney and cardiopulmonary functions meet the following requirements:

‣ Creatinine clearance rate (estimated by CockcroftGault formula)≥40mL/min;

⁃ Total bilirubin≤2×ULN; Alanine aminotransferase (ALT) ≤2.5×ULN and aspartate aminotransferase (AST)≤2.5×ULN;

⁃ Left ventricular ejection fraction \>50%;

⁃ Baseline peripheral oxygen saturation\>95%;

• The venous access required for collection can be established, no contraindications to leukocyte collection, and leukepheresis can be carried according to the judgement of investigators, satisfying hemoglobin≥70g/L,platelets ≥50×10\^9 / L, neutrophils ≥1.0×10\^9/L.