AbstractBecause of the impact of installation error, manufacturing error and elastic deformation and thermal deformation and other factors, the straight bevel gear pair will appear serious phenomenon of meshing interference and impact and uneven load in meshing process, so it is necessary to design suitable modification tooth to improve gear pair's transmission performance and enhance its bearing capacity. In this paper, considering elastic deformation of gear pair, using orthogonal design to obtain the optimal isometric modification parameters, and then using the optimal isometric modification parameters and symmetric crowned modification parameters to modify tooth separately. Three-dimensional solid models of standard gears and modification gears are established by SolidWorks, then dynamic contact FEA is carried out based on ANSYS/LS-DYNA. The simulation results show that the optimal isometric modification can reduce meshing impact and avoid “end contact” and homogenize tooth load distribution more effective compared to symmetric crowned modification for straight bevel gear.