In order to study the vibration response of saturated foundation caused by train moving load under irregular track conditions, and further improve the vibration propagation and attenuation law of saturated foundation, the track irregularity load is introduced into the saturated foundation 2.5D finite element in this paper. The track irregularity load is transformed into frequency domain-wave number domain through Fourier transform, and the vibration response caused by the quasi-static load is compared and analyzed. The results indicate that when the vehicle speed is low, the vibration difference caused by the following two conditions is very small. As the vehicle speed increases, track irregularity significantly increases the amplitude of acceleration and displacement of saturated foundation, and the time-history curves show stronger fluctuation. Track irregularity has little influence on the acceleration spectrum at the center of the track. When the train runs at low speed and high speed, the frequency spectrum rules of the two loads are basically the same, and the main frequency distribution is basically the same. Under the condition of track irregularity, only the acceleration in each frequency band increases slightly. In addition, the pore water pressure of saturated foundation caused by high-speed railway will be greatly increased by track irregularity, and the pore water pressure decreases rapidly with the increase of depth.