Abstract: There is lack of systematic and perfect design and optimization method of Mamdani type fuzzy controller at present. Two design optimization methods were proposed for Mamdani type fuzzy controller of research reactor power regulation system, i.e. uneven distribution membership function of output method and increase and uneven distribution membership function of output method. Control performance of the fuzzy controller after optimization was analyzed on MATLAB/Simulink platform. Simulation results show that performance of the fuzzy controller after optimization is improved, and the performance is better than that of classic PID controller. So, these two design and optimization methods are efficient optimization methods for Mamdani type fuzzy controller.