A New-type Steel Tube Buckling-Restrained Brace with Reinforced Concrete outside (ST-BRB-RC) was introduced in this paper. Six specimens of the ST-BRB-RC were designed and cyclic loading test were carried out to study the hysteretic energy dissipation performance of the six specimens. And then, ABAQUS finite element analysis was used to study the performance of four specimens. The results indicated that the ST-BRB-RC had stable and full hysteretic curve. The bearing capacity of the ST-BRB-RC was stable and the hysteretic behavior was excellent. And the analysis model of ST-BRB-RC could be described by a bilinear model. The construction of the ST-BRB-RC was reasonable, and the energy dissipation mechanism of the ST-BRB-RC was clear. It is proved that the design philosophy of using reinforced concrete for exterior restrained element was available.