This work aims to provide theoretical support for the study of structural loess degradation and slope disaster mechanism under automobile vibration. The research on the dynamic response law of loess stepped slopes under the action of automobile vibration is currently insufficient. Thus, this study takes the loess stepped slope located in Anzi road as the research object and summarizes its deformation modes, failure modes, and characteristics. Vehicle vibration signals of different types, speeds, and positions are obtained by field investigation and monitoring. The following conclusions are derived on the basis of the statistical analysis of the monitoring signals. (1) The vibration response of the slope increases with the increase of vehicle load. As the vehicle load increases, the area with strong vibration response gradually migrates from the second-to the first-grade slope. (2) The amplification effect of the vibration wave is strong when the vehicle load is small and weak when the vehicle load is large. Moreover, the Z-direction wave appears as a vibration attenuation. (3) The X-direction wave's frequency distribution presents a single peak, and the main frequency is concentrated in 17-65 Hz. The Z-direction wave's frequency distribution presents multiple peaks, and the main frequency is concentrated in 22-185 Hz. (4) The frequency variation is not greatly relevant to the type, speed, and position of the vehicle but is determined by the slope itself. (5) The stress state of the loess stepped slope changes under vehicle vibration. In the design of loess stepped slopes, the slope gradient should not be considerably large, and the first-and second-grade slopes should not be extremely high. Furthermore, slope protection should be focused on the first-and second-grade slopes. This research reveals the dynamic response of loess stepped slopes subjected to vehicle vibration, and the results may help establish theoretical and practical methods to protect this slope type.