Abstract: To deduce the analytical formula of large deflection for annular throttle-slices in shock absorbers. Von Krmn equations of annular plate are used to derive the rigidity curve equation for annular throttle-slice in shock absorbers on the basis of Chien-perturbation method. To get the two undetermined coefficients in the rigidity curve equation, high-precision finite element model is set up and carried on numerical tests. For the purpose of getting the analytical formula of large deflection problem for annular throttle-slice, Lorentzian function is used to nonlinear least squares curve sub-fitting for the two coefficients. Numerical results showed that the analytical solution is highly precise.