Abstract: Precast concrete segmental piers (PCSCs) have many advantages such as the short construction time and low traffic and environmental impacts. With the rapid economic development and urbanization, the events of vehicle collision onto bridge piers have been increasing, which in extreme situations may lead to the collapse of the bridge. However, the research on the impact performance of PCSCs under vehicle collision is still limited. Hence it is particularly necessary to carry out the related research. In this study, the numerical simulation of PCSCs under vehicle collision was carried out by the grounds of the explicit dynamic analysis software ANSYS/LS-DYNA. Based on ensuring the rationality and accuracy of the numerical model, the influence of geometric and design parameters on the impact performance of PCSCs under vehicle collision was investigated. These factors included cross-sectional geometry and the arrangement of prestressed tendons and shear keys. The results show that the circular section has better impact performance than the square section under vehicle collision. Besides, compared with the central arrangement, the peripheral prestressed tendons can provide better impact performance for PCSCs under vehicle collision. Moreover, cylindrical concrete shear keys can improve the impact performance of PCSCs by improving the integrity of segmental piers. Based on the research results, for the practical engineering application, PCSCs are better designed with the circular cross-section, and the prestressed tendons should be arranged around the periphery and the shear keys need be arranged at the center of segments.