Inclusion Criteria:

          1. The subject or her/his legally guardian(s) must sign the informed consent form
             approved by the Institutional Ethics Committee (IEC) prior to any screening
             procedures;

          2. Subjects aged 18 years or older with relapsed or refractory DLBCL (including primary
             mediastinal large B-cell lymphoma and transformed follicular lymphoma), of which
             refractory is defined as:

               -  Have no response to the recent treatment including:

                    -  The best response to the treatment regimen is progressive disease (PD) ,or;

                    -  stable disease(SD) which maintained less than 6 months after the last
                       treatment, or;

               -  not suitable for autologous hematopoietic stem cell transplantation (ASCT), or
                  ASCT refractory, including:

                    -  progressive disease after ASCT or relapse within 12 months (relapse must be
                       confirmed by biopsy), or;

                    -  If remedial treatment is given after ASCT, the subject must have no response
                       or relapse after the last treatment.

          3. Subjects who have previously received ≥2 lines treatment, and at least including:

               -  Anti-CD20 monoclonal antibody(rituximab), unless the CD20 negative;

               -  A chemotherapy regimen containing anthracyclines;

               -  The DLBCL patients who transformed from follicular lymphoma must have previously
                  received chemotherapy for follicular lymphoma and have developed
                  chemotherapy-refractory diseases after transform to DLBCL.

          4. Confirmation for either CD19 or CD20 positivity using immunohistochemistry or flow
             cytometry(accepting the previous results from the a third-level grade A hospitals
             before the collection of peripheral blood mononuclear cells or peripheral blood. For
             CD20 positive only, the investigator needs to determine whether the treatment
             benefit);

          5. According to the preliminary assessment of Hodgkin's lymphoma and non-Hodgkin's
             lymphoma, staging and response assessment recommendations (2014 version), there is at
             least one measurable lesion at baseline;

          6. If the subject has received a single target in the past, such as CD19-CAR cell
             therapy, it must be confirmed that the disease has progressed or relapsed after
             treatment and is at least 1 month from the planned single collection period

          7. Life expectancy ≥12 weeks;

          8. Eastern Cooperative Oncology Group (ECOG) performance status that is either 0 or 1 at
             screening;

          9. Adequate organ function:

               -  Renal function defined as:

                    -  A serum creatinine of ≤1.5 × Upper Limit of Normal(ULN), or;

                    -  Estimated Glomerular Filtration Rate (eGFR) ≥60
                       ml/min/1.73m2；[eGFR=186×（age）-0.203×SCr-1.154（mg/dl）， female ×0.742 on the
                       basis of the calculation results]；

               -  Liver function defined as:

                    -  Alanine aminotransferase (ALT)≤ 5 × Upper Limit of Normal(ULN) for age, and;

                    -  Total bilirubin ≤ 2.0 mg/dl with the exception of patients with
                       Gilbert-Meulengracht syndrome; patients with Gilbert-Meulengracht syndrome
                       may be included if their total bilirubin is ≤ 3.0 × ULN and direct bilirubin
                       ≤ 1.5 × ULN.

               -  Must have a minimum level of pulmonary reserve defined as ≤ Grade 1 dyspnea and
                  blood oxygen saturation > 91% on room air;

         10. Hemodynamically stable and Left Ventricle Ejection Fraction (LVEF) ≥ 45% confirmed by
             echocardiogram or Multigated Radionuclide Angiography (MUGA);

         11. Adequate bone marrow reserve without transfusions defined as:

               -  Absolute neutrophil count (ANC) >1×10^9 /L；

               -  Absolute lymphocyte count (ALC) ≥0.3×10^9 /L；

               -  Platelets ≥50×10^9 /L;

               -  Hemoglobin > 8.0 g/dl;

         12. Subjects who use the following drugs should meet the following criteria:

               -  Steroids: Therapeutic doses of steroids must be stopped 2 weeks prior to A-02
                  infusion. However, the following physiological replacement doses of steroids are
                  allowed: < 6 - 12 mg/m2/day hydrocortisone or equivalent;

               -  Immunosuppression: Any immunosuppressive medication must be stopped ≥ 4 weeks
                  prior to sign the informed consent form;

               -  Anti-proliferative therapy other than pretreatment chemotherapy within 2 weeks of
                  A-02 infusion;

               -  CD20 antibody-related treatment must be discontinued within 4 weeks of A-02
                  infusion or 5 half-lives (whichever is longer);

               -  CNS disease prophylaxis must be stopped > 1 week prior to A-02 infusion (e.g.
                  intrathecal methotrexate);

         13. The investigator judged that the subject recovered from the toxicity of the previous
             anti-tumor treatment to grade 1 or below (except for special grade 2 or below toxicity
             that cannot be recovered in a short period of time, such as hair loss), suitable for
             pretreatment. Chemotherapy and treatment of CAR-T cells;

         14. Women of child-bearing potential and all male subjects must agree to use highly
             effective methods of contraception for at least 12 months following A-02 infusion and
             until CAR-T cells are no longer present by Polymerase chain reaction(PCR) on two
             consecutive tests.

        Exclusion Criteria:

        Subjects who meet any of the following criteria will not be enrolled:

          1. Subjects who have received any CD19/CD20 dual-target cell therapy products before
             signing the informed consent form;

          2. Subjects with detectable cerebrospinal fluid malignant cells or brain metastases, or
             with a history of central nervous system (CNS) lymphoma or primary CNS lymphoma;

          3. Subjects with current or previous history of central nervous system disease, such as
             seizures, cerebral ischemia/hemorrhage, dementia, cerebellar disease, or any
             autoimmune disease involving the central nervous system;

          4. Subjects who have previously received allogeneic hematopoietic stem cell
             transplantation (HSCT); or suitable and consenting to Autologous hematopoietic stem
             cell transplantation (ASCT);

          5. Chemotherapy other than lymphodepleting chemotherapy within 2 weeks of A-02 infusion;

          6. Investigational medicinal product within the last 30 days prior to sign the informed
             consent form;

          7. Subjects with active hepatitis B（defined as hepatitis B surface antigen positive, or
             hepatitis B core antibody positive with hepatitis B virus DNA detection value > 1000
             copies/ml）or hepatitis C(HCV RNA positive);

          8. Subjects positive for HIV antibody or treponema pallidum antibody;

          9. Uncontrolled acute life threatening bacterial, viral or fungal infection (e.g. blood
             culture positive ≤ 72 hours prior to A-02 infusion);

         10. Unstable angina and/or myocardial infarction within 6 months prior to sign the
             informed consent form;

         11. Previous or concurrent malignancy with the following exceptions:

               -  Adequately treated basal cell or squamous cell carcinoma (adequate wound healing
                  is required prior to sign the informed consent form);

               -  In situ carcinoma of the cervix or breast, treated curatively and without
                  evidence of recurrence for at least 3 years prior to sign the informed consent
                  form;

               -  A primary malignancy which has been completely resected and in complete remission
                  for ≥ 5 years;

         12. Pregnant or nursing women (women of childbearing age were tested positive for
             pregnancy during screening period);

         13. Subjects with active neurological auto immune or inflammatory disorders (e.g. Guillain
             Barre Syndrome, Amyotrophic Lateral Sclerosis);

         14. Other conditions that the investigator thinks he/she should not be included in this
             clinical trial, such as poor compliance.