Abstract: Linear dynamics analysis method is adopted to obtain stress distribution of high-speed EMU brake caliper structure under random vibration and to identify high failure risk points. By conducting PSD (power spectrum density) analysis on high failure risk points, according to linear cumulative damage hypothesis, the caliper structural failure modes are predicted. A destructive test of physical objects under random vibration with corresponding enhanced amplitude is designed to accelerate the exposure of structural failure, verifying conclusions from the theoretical analysis, and further discussing the failure mechanism.