Objective To explore the spatial distribution of microstructural parameters and mechanical properties for trabecular bone in the femoral head with osteonecrosis. Methods Microstructural parameters and mechanical properties of trabecular bone in different regions were analyzed by combined use of imaging measurements and numerical simulation method, and the spatial distribution of biomechanical properties for trabecular bone along coronal, sagittal and vertical directions was investigated. Results Microstructural characteristics and mechanical properties of trabecular bone were Y-shaped distributed along coronal and sagittal directions, and mechanical properties of trabecular bone in Y-shaped region were higher than those in the other regions. Such distribution characteristics was consistent with the location of principle compressive group in the femoral head. Conclusions Necrotic lesions in Y-shaped region had a greater influence on stress distribution of the femoral head and might cause the deterioration of osteonecrosis. The spacial correlation between necrotic lesions and Y-shaped region should be fully considered during clinical diagnosis.