A Clinical Study Exploring Universal CAR-T Cell in Patients With Relapsed/Refractory B-cell Acute Lymphoblastic Leukemia

Inclusion Criteria: 1. Participants must voluntarily sign the informed consent form (ICF) and must be willing and be able to adhere to the study visit schedule and other protocol requirements 2. 18-75 years old; 3. Histologically or cytologically confirmed B-ALL; 4. Previously received at least 2 lines of systemic therapy; 5. Expected survival \> 12 weeks; 6. Eastern Cooperative Oncology Group (ECOG) score 0-2; 7. Female participants of childbearing potential must have a negative pregnancy test at screening and prior to receiving preconditioning therapy。Both male and Female are willing to use a highly effective and reliable method of contraception for 1 year after receiving study treatment and are absolutely prohibited from donating sperm donation or eggs for 1 year after receiving study treatment infusion during the study. Exclusion Criteria: 1. Pregnant or lactating women; 2. Has HIV, syphilis infection, active hepatitis B virus infection (HBsAg positive and HBV-DNA above the detection limit), or active hepatitis Cvirus infection (HCV antibody and HCV-DNA positive); 3. Has any current uncontrolled active infection, including but not limited to participants with active tuberculosis (investigator 's judgment); 4. Participants' toxicities caused by previous treatment did not recover to Common Terminology Criteria for Adverse Events (CTCAE) ≤ Grade1, except alopecia and other events that are judged tolerable by the investigator; 5. Patients with isolated extramedullary lesions; 6. Vaccination with live attenuated vaccines, inactivate vaccines or RNA vaccines within 4 weeks prior to informed consent; 7. Participants who are allergic or intolerant to preconditioning drugs, tocilizumab, or have other previous history of severe allergy such as anaphylactic shock; 8. Patients with heart disease in the 6 months prior to screening; 9. Presence of a second primary malignancy requiring treatment or not in complete remission within the past 2 years; 10. Serious pulmonary diseases that are judged by the investigator to potentially endanger the patient's life when participating in the study.