Inclusion Criteria:  14-70 years old (including 14, 70 years old), no gender limit; According to the 2020 World Health Organization (WHO) diagnostic criteria, it is diagnosed as relapsed/refractory B-cell acute lymphoblastic leukemia (r/r B-ALL); The ECOG behavior status score is 0-2 points; Expected survival time ≥ 3 months; Flow cytometry confirms that the original cells express CD19; Those who have failed autologous CAR-T cell preparation or autologous CAR-T cell therapy under the existing technical conditions; No serious heart, lung, liver, or kidney disease; Ability to understand and willing to sign the informed consent form for this trial.  Exclusion Criteria:  Primitive cells do not express CD19; Active infection; Abnormal liver function (total bilirubin>1.5×ULN, ALT>2.5×ULN), abnormal renal function (serum creatinine>1.5×ULN); People with unstable angina or New York Heart Association class 3/4 congestive heart failure, multiple organ dysfunction; HIV/AIDS patients; Those who need long-term anticoagulation (warfarin or heparin), antiplatelet (aspirin, dose>300mg/d; clopidogrel, dose>75mg/d) treatment; Those who received radiotherapy within 4 weeks before the start of the study; Known or suspected drug abuse or alcohol dependence; People with mental illness or other conditions cannot obtain informed consent, and cannot cooperate with the requirements of completing the experimental treatment and inspection procedures; Participated in other clinical trials within 30 days; Pregnant or lactating women, male subjects (or their partners) or female subjects have a pregnancy plan during the study period to 6 months after the end of the test, and are unwilling to use a medically approved effective contraceptive measure during the test period (Such as intrauterine contraceptive devices or condoms); Those who are judged by the investigator to be unsuitable to participate in this trial.