<p>In aero-engine, interference fit is employed as the assembly method between the gear bushing and the front journal, where the magnitude and distribution of the contact pressure on the mating surface are critical factors influencing the fatigue failure of the interference fit. Current methods predominantly adopt stress relief groove and chamfer to optimize the contact pressure distribution. However, the associated design parameters lack a solid theoretical foundation and require multiple finite element simulations, which considerably reduces computational efficiency. Therefore, this paper proposes an interference fit profile modification method based on super-element. Based on the equilibrium equations and constitutive equations of the interference fit mating surface, the modifying generatrix of the mating surface is efficiently designed through forward optimization to mitigate edge effect and improve the contact state. Subsequently, the interference fit of a real aero-engine was taken as a case study for profile modification design. Finite element results demonstrated that, after profile modification, the contact pressures at both edges of the mating surface were reduced by 83.6% and 87.3%, respectively. The effective contact length increased by 247.8%, thereby significantly improving the contact state. Finally, ultrasonic testing was conducted to measure the contact pressure distribution of interference fit components without profile modification and with profile modification, and the experimental results verified the effectiveness of the profile modification method. The profile modification method proposed in this study effectively improves the contact interface performance of interference fit and provides a theoretical basis for its structural design.</p>