A three-dimensional seismic response analysis of an asphalt concrete face rockfill dam constructed on a thick overburden layer at the upper reservoir of a pumped-storage power station was conducted using the nonlinear finite element method. The study focused on evaluating the seismic safety of the dam body and the seepage control system. The results indicated that, under the design seismic load, the peak dynamic displacements of the dam body in the horizontal, vertical, and axial directions were 23.87 cm, 10.44 cm, and 26.13 cm, respectively, and the peak accelerations were 2.98 m/s$^2$, 2.01 m/s$^2$, and 2.98 m/s$^2$, respectively. The maximum permanent deformations in the same directions were 18.42 cm, -61.60 cm, and -5.61 cm/18.69 cm, with a settlement ratio of 0.37%. For the asphalt concrete face slab, the peak dynamic displacements in the horizontal, vertical, and axial directions were 23.87 cm, 9.42 cm, and 24.86 cm, respectively. The maximum and minimum principal strains of the face slab after the earthquake were 1.29% and -0.74%. The maximum principal tensile strains of the geomembrane at the reservoir bottom during and after the earthquake were -1.43% and -1.50%. Under the seismic check conditions, the dynamic responses of the dam body, face slab, and geomembrane increased. Comprehensive analysis of the results shows that the seismic response patterns of the dam are consistent with the general characteristics of rockfill dams on thick overburden layers. The dynamic response of the asphalt concrete face slab around the reservoir and the geomembrane at the reservoir bottom did not exceed their respective safety thresholds, indicating that the dam exhibits high seismic safety under seismic loading.