An efficient nonprobabilistic robust reliability method for H∞ robust controller design of parametric uncertain systems is presented by describing the uncertain parameters as interval variables. Design optimization of H∞ robust controller is carried out by solving a robust reliability based optimization problem, by which the disturbance attenuation, control cost, and robust reliability can be taken into account simultaneously. By the method, a robust reliability measure of an uncertain control system satisfying required H∞ robust performance can be obtained, and the robustness bounds of uncertain parameters such that the control cost of the system is guaranteed can be provided. The presented formulations are in the framework of linear matrix inequality and thus can be carried out conveniently. The presented method provides an essential basis for reasonable tradeoff between reliability and control cost in controller design of uncertain systems. Active control design of vehicle suspension is employed for illustrating the effectiveness and feasibility of the presented method.