Objective To investigate the changes in the structural parameters and mechanical properties of the necrotic femoral head and compare the effects of core decompression and bone grafting with those of bone cement filling on the mechanical properties and prevention of articular surface collapse of the necrotic femoral head. Methods Thirty-two fresh human femoral heads were collected from patients who underwent total hip arthroplasty at our hospital between June 2020 and January 2022. The femoral heads were divided into four groups:8 femoral neck fractures (TFF group), 8 osteonecrosis of the femoral head (ONFH group), 8 osteonecrosis of the femoral head treated with cement percutaneous injection (CPI group), and 8 osteonecrosis of the femoral head treated with core decompression and bone graft (CDBG group) . Cement filling or core decompression was performed under radiographic guidance. All samples were scanned and three-dimensionally reconstructed using micro-CT. The spatial heterogeneity of the femoral head was observed, and the bone morphometric parameters of each region of interest were calculated. Mechanical analysis was performed to evaluate the femoral head parameters of displacement and stress in vitro. Results Bone microarchitecture and morphometry in necrotic femoral heads were markedly altered. The biomechanical properties of the necrotic zone in the femoral head were markedly weakened. After the necrotic area was filled with bone cement, the biomechanical properties of the necrotic zone of the femoral head increased significantly. In addition, after core decompression and bone grafting in the necrotic area, the biomechanical properties increased significantly in the necrotic zone of the femoral head. Conclusion Bone cement filling or bone grafting in the necrotic area can change the biomechanical mechanism of the femoral head, improve the load-supporting ability, and prevent femoral head collapse. Cement filling may be a practical approach for the treatment of osteonecrosis of the femoral head that can be useful for practicing orthopedists.