Objective To explore the characteristics of fluid flow within loaded osteons under different boundary conditions. Methods The COMSOL Multiphysics software was used to establish a three-dimensional (3D) finite element model of osteons with different boundary conditions, and the variation rules of pore pressure and flow velocity of osteons under different inner wall pulsating blood pressure and outer wall elastic constraint conditions were analyzed. Results As the pulsatile blood pressure inside the osteon increased from 0 mmHg (1 mmHg=0.133 kPa) to 300 mmHg, the peak pore pressure within the osteon correspondingly increases from 26 kPa to 68 kPa. As the elastic constraint on the outer wall of the osteon changed from being completely elastic to completely constrained, the peak pore pressure within the osteon increased from 15 kPa to 26 kPa, and the peak flow velocity increased from 0.04 μm/s to 0.07 μm/s. Conclusions This study has clarified the influence laws of the changes in boundary conditions such as the pulsatile blood pressure on the inner wall and the elastic constraint on the outer wall of the osteon on the characteristics of fluid flow within the loaded osteon. These findings are conducive to a deeper understanding of the mechanical response mechanisms of bone tissues in both physiological and pathological states, and provide important theoretical bases for further research on bone mechanotransduction.