Abstract: Based on test data,polynomial fitting method is used to establish the theoretical formula for calculating the static spring shear modulus and elastic modulus of the auxiliary spring rubber for rail transit vehicles. Combining mechanics theory and the characteristics of rail vehicle conical spring,the calculation formula about the vertical stiffness of the spring based on the rubber parameters and product structure parameters is established. By randomly selecting conical spring products,the theoretical formula calculation,finite element simulation analysis and calculation,product test are carried out for comparative verification. The results show that the established theoretical calculation formula based on product structure parameters and rubber parameters has a good precision in the linear deformation stage of the conical spring.The theoretical calculation formula can be used for preliminary calculation of vertical stiffness at conical spring design development phase.