In order to screen out which design parameters have significant effects on the vertical vibration model of the railway vehicle, so as to simplify the parameter optimization design of the vehicle model, a global sensitivity analysis method–extended Fourier amplitude sensitivity test (EFAST) is introduced and applied to the parameter sensitivity analysis of a typical railway vehicle vertical model. The analysis results show that, the variations of the secondary suspension parameters and the primary suspension damping parameters have a greater influence on the car body’s bounce motion than the primary suspension stiffness; car body’s pitch motion can be improved considerably by adjusting the length between bogie pivot centers; the interaction between design parameters in the model is small-scale. The research methods and conclusions proposed in this paper have a certain reference value and engineering significance in the vibration characteristics and parameter optimization design of railway vehicle model.