A novel fan-shaped disc energy dissipator (FDED) is proposed in this study. The working mechanism and characteristics of the FDED are illustrated, and its key points and theory of design are derived. The numerical method is used to analyze the seismic performance of the FDED and the influence of different design parameters on the performance of the FDED. Results show that the FDED has a feasible design principle and clear seismic performance. The fan-shaped construction enables the FDED to effectively amplify displacement. The FDED has a bilinear restoring force characteristic, stable energy dissipation performance, and an equivalent viscous damping coefficient that exceeds 50%. Although the change in rubber hardness is insensitive to the initial stiffness of the FDED, it influences the postyield stiffness and equivalent viscous damping coefficient of the FDED. Additionally, as rubber hardness increases, the postyield stiffness of the FDED increases, and the equivalent viscous damping coefficient decreases. The change in the thickness of the single rubber layer negligibly affects the seismic performance of the FDED. The yield force and energy dissipation performance of the FDED are mainly affected by lead-core diameter. Yield force increases and energy dissipation performance improves as lead diameter increases.