Abstract: It is hard to consider the system requirements for both time and frequency domain performances with the current PID optimization methods.To solve this problem,a PID multi-objective optimization design method is proposed: taking dynamic performances as the optimization objectives,and frequency performances as constraints,a multi-objective optimization algorithm based on Pareto optimality is applied to the optimal design.The algorithm employs a new calculation method of crowding distance and double elitism mechanisms,which improves the efficiency of the evolution and more effectively increases the diversity of the Pareto-optimal solutions.And the satisfactory solution is selected in Pareto-optimal solutions according to the requirements of the present system.Simulation results and its application indicate the effectiveness of the proposed algorithm.