In order to improve the plastic deformation capacity of flexural links, a K-eccentrically braced steel frame structure with the dog-bone reduced flexural link was proposed. The effects of the key parameters, such as the weakening starting point a and the weakening depth c, as well as the link spacing of the stiffeners on the seismic performance of the K-eccentrically braced steel frame structure were investigated by numerical simulations. The load carrying capacity, stiffness and energy dissipation capacity between the weakened model and the Base model were compared. The result shows that the weakening starting point a is in the range of 2hf to 3hf, the weakening depth c is in the range of 2tf to 4tf, and the spacing between stiffener is about 07bf, indicating that the difference between the performance of the weakened model and the Base model is not significant. The proposed dog-bone reduced design and the link spacing of the stiffeners can lead to bending plastic deformation in a larger area of the link, so that the energy-dissipating capacity of link is improved, which has some reference value for further study of flexural eccentrically braced steel frame in seismic performance.