Inclusion Criteria:
* 1\. The participant has given consent and signed the informed consent form, and is willing and able to comply with the planned visits, research treatments, laboratory tests, and other trial procedures;
* 2\. Clinically diagnosed as a patient with relapsed/refractory B-cell lymphoma, and confirmed by pathological and histological examination as CD19 and/or CD22 B-cell lymphoma, including: diffuse large B-cell lymphoma, or transformed large B-cell lymphoma from indolent B-cell lymphoma (excluding Richter transformation, THRLBCL, BL). And meets the following criteria (meets any one of the first three items and the fourth): i. Recurrence ≥6 months after achieving remission with first-line full treatment, or ≥12 months after achieving remission following stem cell transplantation; ii. Progression during first-line treatment combined with high-risk factors (double-expressor lymphoma, double-hit lymphoma, TP53 gene mutation or deletion, IPI score ≥3); iii. Disease relapse after ≥2 lines of treatment or failure to achieve remission; iv. The participant has received the following treatment regimens after being diagnosed with LBCL:
* Anti-CD20 monoclonal antibody;
* Combination chemotherapy containing anthracyclines.
* 3\. Age 18 or older, both men and women are eligible;
* 4\. Study participants with an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2;
* 5\. Expected survival of more than 3 months from the date of signing the informed consent;
* 6\. HGB ≥ 60 g/L (transfusion allowed); LYM ≥ 0.3×10\^9/L;
* 7\. Liver and kidney function and cardiopulmonary function must meet the following requirements:
1. Creatinine ≤ 1.5 × ULN;
2. Left ventricular ejection fraction ≥ 50%;
3. Blood oxygen saturation \> 90%;
4. Total bilirubin ≤ 1.5 × ULN; ALT and AST ≤ 2.5 × ULN;
* 8\. Participants intending to become pregnant must agree to use contraception before enrollment in the study and for one year after CAR-T cell infusion; if a participant becomes pregnant or suspects pregnancy, they should immediately inform the investigator.
Exclusion Criteria:
* 1\. Severe heart failure or left ventricular ejection fraction \<50%;
* 2\. History of severe pulmonary function impairment;
* 3\. Concurrent other malignant tumors in the progressive stage;
* 4\. Concurrent severe infection that cannot be effectively controlled;
* 5\. Concurrent severe autoimmune disease or congenital immunodeficiency;
* 6\. History of CAR-T cell immunotherapy;
* 7\. Active hepatitis (hepatitis B virus deoxyribonucleic acid \[HBV-DNA\] or hepatitis C virus ribonucleic acid \[HCV-RNA\] test results above the detection limit);
* 8\. Human immunodeficiency virus (HIV) infection or known acquired immunodeficiency syndrome (AIDS), or syphilis infection.
* 9\. A history of severe allergic reactions to biological products (including antibiotics);
* 10\. Allogeneic hematopoietic stem cell transplant patients who still have acute graft-versus-host disease (GvHD) one month after stopping immunosuppressive agents;
* 11\. Women who are pregnant, breastfeeding, or planning to become pregnant within 12 months;
* 12\. Patients with other serious physical or mental illnesses or abnormal laboratory test results that may increase the risk of participating in the study, or interfere with study results, or who are deemed by the investigators to be unsuitable for participation in this study.
