The traditional metal dampers have the disadvantages such as higher yield point and inadequate adjustability. To overcome these deficiencies, a compound mental damper which comprises the low yield point steel plates and common steel plates is presented. The optimization objectives including “maximum rigidity” and “full stress state” are proposed to obtain the optimal shape of compound mental damper. The numerical simulation results show that the compound mental damper has the advantages such as the full hysteresis performance and uniform stress state, and the integral yield point can be regulated. In view of the mechanical characteristic of the compound metal damper, the equivalent model of eccentric cross bracing is established, and the approximate analytical solution of the yield strength and the yield displacement is proposed. The nonlinear simulation analysis is carried out for the overall aseismic capacity of the frame structures with the compound mental damper. It is verified that the compound mental damper has better energy dissipation capacity and more superior seismic performance, especially for the damper with optimized shape.