The self-centering buckling-restrained brace combined both disc springs and steel tendons （DT-SCB） was proposed to solve the shortage problem of the deformation ability of the traditional self-centering buckling-restrained brace （SCBRB）. The steel tendons in series with combination disc springs are used to provide the self-centering force， and two parallel flat steel cores are responsible for dissipating seismic energy. The detailed configuration， working mechanism at different stages， and restoring force model of DT-SCB were introduced in this study. The finite element model was established， through which the effect of self-centering ratio αsc， the ratio of steel tendons and combination disc springs K1 and the ratio of self-centering unit and energy dissipation system K2 on the hysteretic behavior， self-centering level and energy dissipation capacity of DT-SCB were conducted， respectively. The results indicated that the proposed DT-SCB restoring force model agreed well with that from numerical simulation. No obvious failure characteristics were observed even if the maximum loading displacement （corresponding to the axial strain of 2.5%） was achieved. The hysteretic curve of DT-SCB was flag-shaped， with stable energy dissipation. The deformation ability of proposed DT-SCB was significantly greater than that of the conventional SCBRB with steel tendons. The maximum residual displacement sharply decreased with the increasing self-centering ratio， while the greater K1 weakened the control effect of αsc on residual deformation. The disc springs were prematurely flattened with an excessive ratio of self-centering system and energy dissipation system （K1≥2.0）， which would reduce the deformation capacity of DT-SCB. The stiffness ratio K2 had a significant influence on the energy dissipation capacity of DT-SCB， and the equivalent viscous damper ratio of DT-SCB decreased with the increase of the stiffness ratio K2. The nonlinear dynamic analysis results of the braced frame subjected to severe earthquakes showed that DT-SCB can effectively reduce the maximum and residual inter-story drifts and improve the seismic performance of the frame.