Inclusion Criteria:

          1. Age ≥18 years old;

          2. According to the WHO 2016 classification criteria, the CD20 positive diffuse large
             B-cell lymphoma (DLBCL) diagnosed by pathology should include the indicators of
             immunohistochemistry: CD10, BCL-2, MUM-1, BCL-6 and C-MYC;

          3. Relapsed or refractory DLBCL.Patients younger than 65 years should relapse or progress
             after receiving at least second-line treatment, and patients 65 years of age and older
             could be intolerant to second-line treatment, and they who relapse or progress after
             receiving first-line treatment;

          4. There is at least one measurable lesion, defined as measurable dual-diameter,
             intra-lymph node lesion, short diameter> 1.5cm, extra-lymph node lesion short
             diameter> 1.0cm;

          5. Recurrence confirmed by pathological biopsy and CD20 positive;

          6. ECOG score 0-2 points;

          7. No autoimmune diseases;

          8. Blood routine examination meets the following criteria:

               1. Neutrophil count ≥ 1.5 x 109 / L,;

               2. Platelet ≥ 75 x 109 / L,;

               3. Hemoglobin ≥ 10.0 g / dL;

          9. The main organ function meets the following criteria:

               1. Aspartate aminotransferase and alanine aminotransferase ≤ 2.0 times the upper
                  limit of normal value;

               2. Bilirubin ≤ 2.0 mg / dL;

               3. Creatinine clearance rate ≥ 60 mL / min;

         10. Patients must agree to take effective contraceptive measures during the study
             according to the investigator's request;

         11. Understand and voluntarily sign written informed consent.

        Exclusion Criteria:

          1. Diagnosed as transformed diffuse large B-cell lymphoma;

          2. Diagnosed as double-hit diffuse large B-cell lymphoma (DHL);

          3. Diagnosed as primary or secondary central nervous system lymphoma;

          4. HBV DNA positive or HCV RNA positive patients;

          5. Left ventricular ejection fraction <50%;

          6. Patients with history of autoimmune diseases, including but not limited to systemic
             lupus erythematosus, rheumatoid arthritis, Sjogren's syndrome, ankylosing spondylitis

          7. Patients are using or have been used immunosuppressive drugs

          8. Patients with ≥2 grade peripheral neuropathy