This is a single-center, single-arm, prospective exploratory study designed to evaluate the safety and efficacy of luspatercept for the treatment of anemia following allogeneic hematopoietic stem cell transplantation in patients with acute leukemia. A total of 46 eligible subjects are planned to be enrolled. The primary efficacy endpoint is the proportion of patients achieving a hemoglobin increase of ≥1.5 g/dL at 8 weeks post-transplantation (without transfusion support) compared to baseline (the average of 3 days prior to the first dose). Secondary endpoints include assessing the impact of luspatercept on time to hematopoietic engraftment (neutrophil and platelet) and recording safety indicators such as adverse events, graft-versus-host disease, and infections. Subjects will receive subcutaneous luspatercept at 1 mg/kg on day +7 and day +28 post-transplantation.