Abstract: The Bode's ideal transfer function is applied to the design of fractional order controller and the parameter tuning of fractional order PID controller.The resulting controllers can make the curve of phase frequency Bode plot for the compen-sated system flat at the given gain crossover frequency,under the premise of ensuring that the given gain crossover frequency and phase margin are fulfilled.Therefore,the closed-loop system is robust to gain variations.The methods proposed can promote the performances of the closed-loop systems and suit for fractional and integral order objects.Simulation results demonstrate the effectiveness and validity of the proposed method.