Abstract: Objective: To establish a scientific, objective and practical knowledge system in nuclear emergency for nurses. Methods: The preliminary knowledge indicators were formulated based on literature review, related regulations and the emergency nursing rescue process in nuclear accident. Then, the indicators were determined by two rounds of Delphi consultation. Results: The nuclear emergency knowledge system included 3 first-level indicators, 12 second-level and 48 third-level indicators. The experts' authority and reliability were high. Conclusion: The knowledge system could provide a scientific tool for evaluating the nurses' nuclear rescuer knowledge level. It is also helpful for nurses' training.