Abstract: When train is passing track bed of some intervals, its wheel-rail excitation can cause coupled resonance of axle box cable bracket, resulting in abnormal fracture of the axle box grounding terminals. Targeting this problem, finite element model is established for simulation, and the inherent modal characteristic of the original bracket is identified through hammer test. According to vibration transmission path analysis, the primary transmission path is identified to be rail →axle box →wire splint →bracket →grounding terminal, and rail →axle box →grounding terminal is the secondary path. Optimization schemes of bracket and terminal are proposed accordingly. The test results from high frequency excitation vibration test bench indicate that the scheme with short cantilever is better than that with variable cross-section, and modifying the terminal structure can also decrease stress level. The line verification test results show that the optimization scheme with 8 mm thick short cantilever can drastically decrease the stress level of bracket and terminal, demonstrating evident improvement.