Applying the seismic energy dissipating damper in the self-centering structure can reduce the damage of the beam and column caused by the earthquake. The structure can be quickly restored by replacing the damaged dampers. We propose a new buckling restrained L-shape superimposed steel damper connecting with high-strength bolts which can dissipate the most seismic energy through the steel plate. The proposed damper can avoid the buckling of the steel plate through the additional restraining devices, and easily be replaced after earthquake. The flange of the beam end can be reinforced by the new damper, which also can be regarded as a shear transfer device. The consequences of the axial tension and compression test and ABAQUS simulation indicate that the proposed buckling restrained L-shape superimposed steel damper has essential capabilities of energy dissipation and good bearing and stiffness with the sufficient connecting strength.