Abstract: Based on the analysis for bud shaped composite sealing ring of hydraulic support, nonlinear problems and contact problems of finite element analysis, this paper expounds the material properties of the rubber, polyurethane, basic theory and constitutive model of rubber elastomer, and characterizes the material properties of rubber and polyurethane with Mooney-Rivlin model of different constants.Through uniaxial tension and compression tests of rubber and polyurethane, the parameters of Mooney-Rivlin model of two kinds of materials are obtained.According to the experimental parameters, the finite element analysis is made on the bud shaped composite ring, which is found to be suitable for the dynamic seal.As the loading increases, the sealing effect decreases.The research has reference significance to the design of the seal.