Allogeneic bone grafting, as an alternative to autograft, is an effective hip preserving method that can be employed to delay or arrest the progression of the femoral head necrosis (FHN), and it can help to obtain the load balancing between subchondral cortical and cancellous bone, strengthen structural mechanics of the femoral head and provide biology repair materials for bone regeneration during bone healing. However, these conclusions have been drawn primarily from observational clinical experience and lack of biomechanical basis. The purpose of this study was to evaluate the efficacy of biomaterial allograft bone for the treatment of FHN using computational biomechanical models. The results showed that allogeneic bone grafting reduced the collapse risk of the necrotic femoral head and recovered the load share ratio between the cortical bone and trabeculae in weight-bearing areas. This study provided a considerable direction using computational biomechanical technology for orthopedic research and specific biomechanical evidence for the use of allogeneic bone grafting in clinics.