To study the seismic performance of the connection system of precast concrete with a metallic damper, numerical simulation analyses of the connection system and ordinary prefabricated assembly frame are carried out; the influence of different design parameters of the damper on the seismic perfor-mance of the system is also analyzed. The connection system of the metallic damper shows better seismic performance than ordinary precast concrete frames, which could delay beam end damage, and effectively solve difficulties associated with construction of the subsequent concrete casting area at the beam end. Decreases in metallic damper height improve the energy dissipation ability but reduce the initial stiffness and bearing capacity. In addition, as the height of the energy dissipator increases, the larger the mid-span bending moment of the member and the earlier it yields. However, the oversize of the energy dissipator leads to severe bending deformation.