Optimal adhesion control is an essential prerequisite to ensure the safety and reliable operation of high-speed trains. This paper proposes an optimal adhesion control method in high-speed train using Lyapunov-based control with slide mode extremum seeking. The proposed optimal control techniques aim to track the desired creep velocity, adjust traction force, and reduce wheel slip by identifying the maximum adhesion point in various track surface conditions. Firstly, a high-speed train single-axle dynamics model is established. Secondly, In the actual operation of the train, the adhesion coefficient changes with the state of the track surface at all times, and the adhesion coefficient cannot be directly measured, the estimation of the adhesion coefficient of the full-dimensional observer is established. Then slide mode extremum seeking is established to track the optimal slip velocity. Finally, the Lyapunov-based controller is established to achieve optimal adhesion control. The effectiveness of the proposed optimal adhesion control strategies is validated through theoretical analysis and simulations carried out in MATLAB Simulink. From the result of simulations, the proposed method can track the optimal slip velocity when the wheel-rail contact condition changes suddenly and can achieve optimal adhesion control.