Aviation spiral bevel gears operate under complex loads and require efficient lubrication. Accurately characterizing tooth surface roughness is critical for analyzing elastohydrodynamic lubrication. This study used a multi-functional friction and wear test bench to measure the rough morphology of gear teeth, followed by necessary treatments. An elastohydrodynamic model incorporating real surface roughness was developed to simulate lubrication under operational conditions. The results show that oil film pressure peaks correspond to surface roughness, with maximum pressures at the tooth root, pitch line, and addendum increasing by 15%, 50.76%, and 5.48%, respectively, compared to a smooth surface. Oil film thickness patterns align with smooth surface analysis but are reduced by 2.99%, 3.47%, and 3.67% at the root, pitch line, and addendum. Friction coefficients also increase, with the highest values at the tooth root and top, indicating these areas are more prone to wear. This study highlights the impact of rough topography on lubrication performance, offering insights to improve gear reliability.