High-pier large-span continuous rigid frame bridges in mountainous areas with high-intensity earth-quakes are characterized by large variations in pier height, heavy weight of the upper structure, and large seismic forces. Therefore, seismic performance is a key design consideration for these bridges. To improve the seismic performance of large-span continuous rigid frame bridges, this paper studies seismic reduction techniques from the aspects of pier type optimization and pier stiffness matching. The results show that (1) the robust framed reinforced concrete pier structure adopted for the main pier can reduce the weight of the lower structure, reduce the stiffness of the pier, and reduce the seismic force on the pier and (2) optimizing the section sizes of the high and low piers and adjusting the pier stiffness can match the bearing capacity of each pier with the seismic force it receives.