Abstract: A design method was proposed for robust controller with given structure based on multi-objective genetic algorithm (GA) and static H_∞ loop shaping procedure. Using the method, a controller for steam generator water level at low load with structure of proportional-derivative cascaded filter was designed, with which simulation tests were carried out on response of the control system under step changes of both the water level and steam flow as well as at pressure fluctuation of the feed water. Simulation results show that the robust stability and performance of the designed control system are better than those of other three H_∞ loop shaping based schemes, via the derived controller, higher control quality and stronger robustness may be obtained under given step changes of feed water and steam flow.