A radiation protection control system has been designed, based on distributed computers and consideration of the features of the radiation source of the HT-7U fusion experimental device, for protecting the workers and the public against neutron and photon radiation, and especially for ensuring that workers cannot unexpectedly enter an area of high radiation level in any case. A multisubsystem (irradiation monitoring subsystem, access control subsystem, safety interlock subsystem and other related facilities) integration concept is proposed for the design. This system has been implemented on the basis of the up-to-date industrial field bus CAN, featuring simplicity and flexibility of installation and maintenance, capability for real-time long distance communication and multi-master protocol.