Abstract Low hysteresis brush seals are frequently utilized in high-temperature, high-pressure, and high-speed environments. It is crucial to note that the high-speed rotor will contact the bottom end of the bristles, generating a significant amount of frictional heat. This heat can directly impact the sealing performance and service life, and high temperatures can exacerbate the frictional heat. This paper presents the cyclical testing of the low hysteresis brush seal with increasing and decreasing speed at different pressure differences and temperatures. The study focuses on the leakage characteristics, hysteresis effect and the temperature-rise of the bottom end of the bristles caused by frictional heat. The findings indicate that higher temperatures result in increased leakage, stronger hysteresis effects, and lower temperature-rise. Additionally, as the speed exceeds 6000rpm, the temperature-rise increases more rapidly due to frictional heat. During the speed decrease stage, the temperature-rise decreases sharply at first and then gradually decreases until it is almost unchanged. The hysteresis effect results in a lower temperature-rise during the speed-decrease stage compared to the speed-increase stage. The low hysteresis structure can effectively reduce hysteresis effect compared with the conventional brush seal. However, this structure may result in larger leakage. To minimize leakage, it is necessary to select a more suitable size for the pressure relief chamber. Furthermore, the low hysteresis brush seal exhibits a lower friction temperature-rise compared to the conventional one, which is beneficial to the service life of the brush seal.