Abstract:Objective Bones have composite hierarchical structures, and different hierarchical levels exhibit diverse material properties and functions. To construct a multiscale model of the cortical bone that includes different biological functional units, investigate the conduction behavior of fluid flow induced by physiological loads at different scales of bone. Methods The COMSOL Multiphysics software was used to establish multiscale bone models, and the fluid behaviors were investigated through macro-, meso-and micro-scale. Results The maximum values of the pore pressure and fluid velocity was observed in the position of periosteum at macro-meso scale,and the minimum values was observed in the position of endosteum. The changes of pore pressure, fluid velocity and fluid shear stress of lacunae and canaliculi along the radius of bone tissue and osteon were analyzed at meso-micro scale. Due to the different structure and material parameters in different layers, the loading and fluid pressure caused different biomechanical responses in the process of transferring from macroscale to microscale. Conclusions A multi-scale bone model including whole bone structure,osteon,lacuna and canaliculi was established for a section of bone tissue, which provided a theoretical reference for a deeper understanding of fluid stimulation and mechanotransduction.