⁃ Participants must meet all of the following criteria to be enrolled:

• Patients must voluntarily sign the informed consent form (ICF) and must be willing and be able to adhere to the trial visit schedule and other protocol requirements and agree to be in long term follow-up (LTFU) for up to 15 years as mandated by the regulatory guidelines.

• Age ≥ 18 years;

• Patients with R/RMM who have received at least 3 prior lines of therapy, including at least 1 proteasome inhibitor and at least 1 immunomodulator (IMiD). Patients with RRpPCL had received at least 1 prior line of therapy. Number of lines of therapy was defined according to the guidelines provided in Rajkuma\[1\]r 2015 . Patients must have received at least 1 complete cycle of therapy for each line of therapy.

• According to multiple myeloma IMWG 2016 and plasma cell leukemia IMWG 2013, patients must have progressive disease following or during the last treatment.

• Patients must have measurable disease based on at least one of the following parameters:

• Expected survival \> 12 weeks;

• Eastern Cooperative Oncology Group (ECOG) score 0- 1 ;

• Patients should meet the following test results

• Female patients of childbearing potential must have a negative pregnancy test at screening and prior to receiving lymphodepletion therapy and are willing to use a highly effective and reliable method of contraception for 1 year after receiving study treatment and are absolutely prohibited from donating eggs for 1 year after receiving study treatment infusion during the study ;Male patients are willing to use a highly effective and reliable method of contraception for 1 year after receiving study treatment if they are sexually active with a female of childbearing potential. Sperm donation is absolutely prohibited within 1 year following study treatment infusion for all male patients during the study.