In order to study the leakage characteristics of low-hysteresis brush seal with deflector plate and the bristle pack deformation,ANSYS software was used to establish the numerical analysis model of low-hysteresis brush seal.Considering the flexible effect of the deflector plate,the rationality of the numerical model was verified by comparing the simulation results with the relevant experimental data.The effects of four different structural parameters on the leakage characteristics of low-hysteresis brush seal were studied,and the leakage and bristle pack deformation of low-hysteresis brush seals with and without deflector plate were compared.The results show that deflector plate helps to improve the sealing effect of low-hysteresis brush seal.The leakage of the low-hysteresis brush seal with deflector plate is small,and the leakage is positive correlation with the protection height and radial clearance,and is inversely correlated with the deflector plate length.The deflector plate can reduce the maximum deformation and the equivalent stress of the brush wire,and the aerodynamic force and axial deformation of the brush wire increase with the increase of the pressure difference.The maximum deformation occurs at the tip of the first row of the brush wire near the rear baffle.