A Triple-targeted Cell Preparation Targeting CD19/CD20/CD22 in Patients With Relapsed/Refractory B-cell Acute Lymphocytic Leukemia

Inclusion Criteria: 1. Subjects have fully understood the possible risks and benefits of participating in this study, are willing to follow and able to complete all trial procedures, and have signed informed consent; 2. Age 18-75 years; 3. ECOG score: 0-1; 4. Detect the expression of at least one of CD19/CD20/CD22 in leukemic cells by Flow cytometry in peripheral blood or bone marrow 5. Leukemia cells in the bone marrow \>5% 6. Pathologically confirmed relapsed/refractory ALL must meet one of the following conditions: 1. Naive patients who failed to achieve CR1 after standard chemotherapy; 2. relapse within 12 months after CR1, or relapse after 12 months but fail to achieve CR2 3. twice or more bone marrow relapse 4. Philadelphia chromosomal positive (Ph+) and unable to tolerate TKI therapy, failed TKI therapy more than 2 lines, or had contraindications for TKI therapy 7. Clinical laboratory values meet screening visit criteria 8. Expected survival ≥ 3 months; Exclusion Criteria: 1.Prior antitumor therapy with insufficient washout period; 2.CNS infiltration; Except for patients with prior CNS infiltration who are currently in remission; 3.Have received two or more targets (CD19/CD20/CD22) CAR-T cell therapy (including but not limited to sequential infusion) at any previous time, or have received CAR-T cell therapy from Camel family origin; 4.With acute or chronic graft-versus-host disease; 5.Isolated extramedullary relapse, but hepatic, spleen, or lymph node-isolated extramedullary relapse is acceptable; 6.HBsAg, HBV DNA, HCV-Ab, HCV RNA or HIV-Ab positive; 7.Pregnant or lactating women; \-