Abstract: Although cable tray supports are simple in structure, their seismic analysis calculations are still time-consuming. In order to get an assessment method that can evaluate cable bridges quickly and instantaneously, this study simplifies the S2 type supports vibration problem into a cantilever beam vibration model with mass points at the end. According to the structural characteristics of the supports, we investigates its influence on the participation coefficient and vibration pattern of the cantilever beam in terms of the size and position of the mass points in the cantilever beam. The results show that the cantilever beam with mass point at the end is suitable for assessing the self-vibration frequency and bending stress of the cable bridge, and the results are compared with the reaction spectrum analysis method and the seismic identification test results, and the results are in good agreement. The cantilever beam model with mass points at the end can characterize the vibration of type S2 supports, which can meet the immediate assessment of type S2 cable supports, provide empirical support for project site designers, give quick design advice, and can also be used as a basis for preliminary design.