Currently, research into vehicle loads’ influence on support structures of foundation pits is still at an initial stage. Through field measurements of vehicle load and vibration acceleration of foundation pits’ retaining structures, as well as dynamic earth pressure of a retaining pile following the action of vehicle load. Empirical formulas for the calculation of vehicle load on adjacent foundation pits were obtained, and the influence of vehicle load and vehicle speed on the vibration characteristics of retaining structures and dynamic earth pressure were analyzed. Results showed that vertical vibration gives priority to the vibration induced by vehicle load at the ground surface. Vehicle load directly influences the amplitude of the vibration acceleration of both the foundation pit retaining structure and the dynamic earth pressure. Vehicle speed also has an effect on the peak acceleration induced by vehicle vibration, and higher speed will lead to larger peak vibration acceleration and dynamic earth pressure. However, the influence of vehicle load will decrease with increasing distance. These results can provide a reference for design and construction of relevant foundation pit projects.