This study investigates the effect of high-peak loads on local relaxation of residual stress and fatigue damage in HFMI-treated high-strength steel welded joints. The finite element simulations are applied to consider the combined effect of geometry, material, and residual stress. This simulation model specifically contains the actual treated surface profile with material imperfections. As a result, the material imperfections highly influence the local elastic-plastic behavior under load conditions, including a high tensile and compressive peak load, thus the local relaxation of residual stress and fatigue damage. The results provide further understanding towards a robust modeling approach to the fatigue life estimation of HFMI-treated welds subjected to high-peak loads.