Abstract: Supercritical Water-cooled Reactor（SCWR） is the only water-cooled reactor proposed for the Generation IV nuclear system. The dynamics of its steam temperature are strongly influenced by the reactor power and also with a high degree of nonlinearity. It is difficult to control using the traditional PI control only. In this paper, moving boundary method is adopted to construct the dynamic model of the steam temperature in a Canadian SCWR. The design of the feedforward controller and fuzzy adaptive PI controller is based on the dynamic characteristics of the steam temperature. Through numerical simulation, it is found that the feedforward control can reduce the effect of the reactor power on the steam temperature. The control parameters can be tuned online using fuzzy adaptive control and the control performance can be improved. Steam temperature can promptly stabilize and the variation is reduced using the designed fuzzy control system. It is concluded that the control performance is much better than that with PI controller and the control requirements of Canadian SCWR are satisfied.