We present a method for computing annular slice deflection. The physical model of throttle slice was built. The equation for deformation under a uniform load was deduced by using a deflection differential equation for throttle slice and boundary condition, which was convenient for theory analysis and engineering application. Equation correctness was validated by comparing the approximated result in the existing technology. We subsequently studied the rules of different loads, structure parameters, and material characteristics of throttle slice influence on the deformation at any radius. The equation and conclusions can serve as references for accurately designing shock absorber throttle valves.