Aplastic anemia (AA) is a rare bone marrow failure syndrome with an annual incidence of about 0.74/100,000, affecting all ages but more common in the elderly. It's divided into congenital and acquired forms, with the latter being more prevalent. The primary acquired form is linked to T lymphocyte activation and genetic factors. The best treatment is allogeneic hematopoietic stem cell transplantation (allo-HSCT), with a near 90% cure rate. Sibling allo-HSCT is ideal but finding a match is challenging. For those who relapse after immunosuppressive therapy, haploidentical HSCT is a viable option despite risks like graft failure and GVHD. Advances in transplantation have made haplo-HSCT's efficacy comparable to other methods. Recent studies suggest co-transplantation with umbilical cord blood cells can improve outcomes by hastening hematopoietic recovery and prognosis. Our study will evaluate the feasibility and safety of this approach in AA treatment, comparing it to sibling fully matched transplantation, with a focus on infection rates, GVHD incidence, TRM, and EFS, aiming to enhance treatment practices and benefit patients and the medical industry.