Inclusion Criteria:  Participants must be able to understand and be willing to sign a written informed consent document; Men and woman who are at least 18 years of age on the day of consenting to the study; According to the WHO 2016 classification criteria, pathologically confirmed CD20+diffuse large B-cell lymphoma; Patients with MYD88 and CD79A/B mutations or CD79B alone; Relapse or progression after treatment with at least two prior therapies; There is at least one measurable lesion, defined as a two-path measurable, intraductal lesion short neck >1.5cm, extranodal lesion short diameter >1.0cm; Eastern Cooperative Oncology Group (ECOG) performance status =< 2  Blood routine examination meets the following criteria:  Neutrophil count ≥ 1.0 x 109 / L; Platelet ≥ 75 x 109 / L; Hemoglobin ≥ 10.0 g / dL;  The main organ function meets the following criteria:  Aspartate aminotransferase and alanine aminotransferase ≤ 2.0 times the upper limit of normal value; Bilirubin ≤ 2.0 mg / dL; Creatinine clearance rate ≥ 60 mL / min;  Must agree to effective contraception  Exclusion Criteria:  Transformed diffuse large B-cell lymphoma; HBV DNA positive or HCV RNA positive; Patient is known to have an uncontrolled active systemic infection; Left ventricular ejection fraction < 40%; Previous autoimmune diseases, including but not limited to systemic lupus erythematosus, rheumatoid arthritis, dry syndrome, ankylosing spondylitis, etc; Immunosuppressive drugs are being or have been used in the past; Known hypersensitivity to the study drug or any of its excipients; There are other active malignant tumors that may interfere with this study requiring treatment; Known history of human immunodeficiency virus (HIV) infection; Previous autologous stem cell transplantation or allogeneic hematopoietic stem cell transplantation; The investigator judges that the patient has other inappropriate circumstances.