This is a prospective, multicenter, randomized controlled trial designed to evaluate whether short-term blinatumomab intensification before allogeneic hematopoietic stem cell transplantation (allo-HSCT) can improve survival outcomes in adults with high-risk BCR::ABL1-negative B-cell acute lymphoblastic leukemia (B-ALL) who have achieved measurable residual disease (MRD) negativity. Blinatumomab, a CD19/CD3 bispecific T-cell engager, has shown promising efficacy in eradicating MRD and prolonging survival in B-ALL patients. In this study, eligible participants will be randomly assigned to receive either short-term blinatumomab consolidation prior to allo-HSCT or proceed directly to allo-HSCT. The primary endpoint is relapse-free survival (RFS). This study aims to optimize treatment strategies and improve long-term outcomes for patients with high-risk BCR::ABL1-negative B-ALL.