The failure mode and effects analysis of the digital?I&C system of nuclear power plant are carried out, and puts forward two failure modes of the digital I&C system of nuclear power plant: "all DCS man-machine interfaces are lost" and "DCS control layer failure". By analyzing the monitoring information required for the stable operation of the plant?and the safe shutdown demand of the plant?after abnormal parameters, the backup control?concept based on the integration of digital display instrument, alarm lamp and operation switch is proposed for the first time, and a conventional island backup control?panel is developed. The number and type?of digital display instruments and alarm lights on the conventional?island backup?control?panel meet the monitoring requirements for the stable operation of the plant?within a limited time under the condition that “all DCS man-machine interfaces are lost”. The number and type of operation switches on the conventional?island?backup?control?panel?meet the requirements for safe shutdown of the plant?in the case of "all?DCS?man-machine interfaces are lost"?and "DCS control layer failure".?The nuclear power plant?is equipped with a conventional island backup control?panel independent of DCS to maintain the safe operation of the nuclear power plant?within a certain time when all the computer information and control system of the power plant?are lost, and can bring the nuclear power plant?into a safe shutdown state, so as to realize the diversity of the instrument and control platform of the nuclear power plant?and prevent the loss of monitoring function due to common cause failure in a set of platform.