Abstract: In order to solve the problem that traditional displacement-related braces have small deformation and are difficult to fully exert their working performance under low-intensity earthquakes, a torsional displacement-amplified brace (TDAB) is proposed upon the bridge amplification working mechanism. Its basic structure and working mechanism are introduced first, and then a theoretical restoring force model for TDAB is deduced upon the elastic, elastoplastic and complete plastic deformation stages. Through numerical simulation, the hysteretic properties, equivalent damping ratio and plastic deformation of the TDAB at different initial magnification angles are investigated , and the seismic performance of a double-column pier structure with the TDAB proposed is analyzed. The results show that the theoretical restoring force model can effectively describe the hysteretic performance of the TDAB, which is in a good agreement with the numerical simulation results. With the decrease of the initial magnification angle α₀, the yield bearing capacity, maximum bearing capacity, initial stiffness and energy dissipation capacity of the TDAB increase significantly. When designing the size of the force transfer rotating plate reasonably, the maximum tension-compression load ratio of the brace can meet the specified limit of 1.3, but it is still recommended to adopt the inverted V or herringbone support layout to meet the balanced seismic performance requirements of the structure in the positive and negative loading directions. The TDAB shows an excellent seismic control performance when being applied to a double-column pier structure with different initial amplification angles. The maximum pier top displacement, maximum plastic rotation and shear force of the double-column pier structure equipped with the TDABs all decrease obviously, and the seismic performance can be further improved by reducing the initial amplification angle of the TDAB.