Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an important treatment for hematological malignancies. Poor erythroid engraftment after transplantation is a serious complication, especially in patients with moderate to severe myelofibrosis (MF). Currently, there is a lack of effective prevention strategies for poor erythroid engraftment after transplantation. Luspatercept, a novel TGF-β superfamily signaling pathway modulator, has shown potential in small-sample studies for the treatment and prevention of post-transplant anemia. Given the high proportion and poor prognosis of poor engraftment function in hematological malignancies with moderate to severe myelofibrosis after transplantation, we plan to conduct a prospective, multicenter, randomized controlled study to explore the efficacy and safety of luspatercept in preventing poor erythroid engraftment after allo-HSCT in hematological malignancies with moderate to severe myelofibrosis.