The post-tensioned steel strand and energy dissipation bars are used to a self-centering steel truss beam to dissipate energy and reduce effectively residual deformation of the structure, respectively. The theoretical value of moment capacity and stiffness at end of beam are deducted correspond to major points of its backbone of their hysteretic curve. The nonlinear mechanical properties of beam are analyzed by Open Sees. the simulation results such as moment and stiffness are very consistent with theoretical analysis results, thus the effectiveness of nonlinear analytical model is proved. The nonlinear analysis results show that the steel truss beam is capable of self-centering and energy dissipation under cyclic loading.