To study the influence of a base isolation system on the seismic performance of rotational cable-stayed bridges, the Taichengxi Bridge on the newly-built Fuzhou-Xiamen passenger line was taken as the engineering background. A dynamic model of the entire bridge was established for a nonlinear time-history analysis. Seven seismic waves and five groups of base isolation schemes with curved surface friction pendulum bearings were selected to compare and analyze the seismic performance of the rotational cable-stayed bridge. The results showed that the natural period of the bridge increased, and the global stiffness and seismic response decreased evidently after adopting the base isolation system. Although the curved surface friction pendulum bearing had little influence on the structural deformation, it significantly reduced the internal force; therefore, it can be used as an isolation bearing in rotational cable-stayed bridges. With the adoption of the base isolation system, the bending moment at the bottom of the main pier could be reduced by 44.83%-55.82%, the shear force could be reduced by 40.3%-63.09%, and the maximum displacement in the rigid fixity zone of the tower and girder was 65.53 mm.