Abstract: To investigate the seismic behavior of steel frame-bent structure with energy dissipation braces, single specimen of five-story steel structure with BRB (buckling restrained brace, BRB) selected from a thermal power plant main building was designed. Failure mechanism, hysteretic capacity, stiffness degradation law, inter-story displacement and energy dissipation capacity of BRBs were analyzed through low cyclic loading tests. The results show that steel frame-bent structure with energy dissipation braces has good lateral stiffness and bearing capacity. The specimen shows good ductility and energy dissipation capacity, being of plump spindle hysteretic loops, and the equivalent viscous damping coefficient reaches 0.262, and the coefficient of displacement ductility exceeds 3.53. The BRB starts to yield at smaller loading displacement before beam-column yields and the energy dissipation characteristic is obvious, so the viscous damping of structure is increased, resulting in an improved seismic performance.