We report the design and simulation of a dual-band perfect terahertz absorber which is composed of an electric Split-Resonance-Ring(eSRR)layer,polyimide spacer and a metal plate layer.The absorber has two near-unity absorptions near 0.502 THz and 0.942 THz and both are related to the LC resonance of the eSRR.The results show that the designed terahertz absorber is an excellent electromagnetic wave concentrator.The electromagnetic waves are firstly converged into the spacer and the eSRR layer and are then significantly absorbed.