Sliding bearings represent a prevalent type of bearing in cable-stayed bridges, and are also one of the important force-transmitting components of bridges. Sliding bearings are often worn during operation, resulting in the load transfer function and the displacement and rotation deformation function being affected, and there are certain hidden dangers to the safe operation of bridges. Therefore, it is of great significance to analyze the influence of sliding bearing performance changes on the overall mechanical properties of cable-stayed bridges. Based on the finite element model of cable-stayed bridges considering bearing wear, this paper analyzes the influence of sliding bearings on the static and dynamic performance of cable-stayed bridges in different degrees of wear. Taking a cable-stayed bridge as an example, a spatial three-dimensional finite element model of a cable-stayed bridge considering sliding bearing wear and other boundary conditions is established. The displacement-friction relationship of sliding bearings during progressive wear is simulated. The modal performance, static performance and dynamic response of the cable-stayed bridge are comparatively analyzed when the sliding bearings are worn to different degrees, and the degradation law of the overall mechanical properties of the cable-stayed bridge is obtained when the sliding bearing is damaged. The findings of the study demonstrate that the occurrence of sliding bearing wear leads to an augmentation in bridge stiffness. This, in turn, results in an escalation in the frequencies of the cable-stayed bridge, especially for longitudinal drift and vertical bending modes, increases the girder end axial force significantly and reduces the cumulative bearing displacement. The bearing cannot adapt to the deformation needs of the girder, resulting in a buildup of internal forces in the girder and bearings.