This paper proposes a high-speed rotating thermo-solid coupling finite element model for lip seal, which simulates the lip temperature changes during rotation by cyclically applying thermal loads to achieve lip temperature distribution characteristics. Considering the influence of working condition parameters and structural parameters, the lip temperature and sealing interface contact pressure distribution are obtained, and the lip seal structure is optimized. The results show that ignoring the uneven distribution of lip friction heat will lead to a 25.6% error in the radial force. The optimized lip seal yields an impressive 14.3% reduction in leakage rate compared to the original configuration, showcasing a significant performance enhancement in lip seal.