The force of the rubber sealing ring in the brake and release of the brake cylinder affects the braking performance of the vehicle.Through the measurement of the size of sealing groove and rubber sealing ring,the force of dynamic and static friction process between the piston and the sealing ring was tested.Based on the Yeoh hyperelastic model,the stress and strain characteristics of the rubber sealing ring under preloading state,braking state and brake release state were analyzed by reasonable determination of the simulation parameters.The influence of the relevant characteristics of the rectangular rubber sealing ring of sealing groove structure in the brake cylinder,and the brake friction material were discussed and analyzed.The results show that during the braking process,the actual displacement of the piston is very small.When the brake is released,the separation gap between the brake disc and the friction material is very small,and the disc and the friction material will be in a slight contact state.The inclined groove structure can ensure good sealing effect and reduce the inner stress of rubber ring.