Abstract: Cold source security technology of nuclear power in sea ice region is concerned by managers and scholars, since the first nuclear power stations in China -Hongyanhe Nuclear power plant built. In this paper, according to the monitoring requirements of sea ice project, we analyzed the advantages of radar in monitoring sea ice in coastal waters, designed the sea ice monitoring system based on radar technology, and introduced the application of the system in the Hongyanhe Nuclear power. The real-time sea ice information provided by the system can provide the basis for the relevant departments to take effective measures to prevent and reduce disaster.