The equipment and cables of the various plants of Nuclear Power Plant are complex, which greatly improves the possibility of electrical equipment being subjected to electromagnetic interference, and electromagnetic interference is mainly reflected in the interference of digital, pointer-type instrumented systems and automatic control systems, resulting in false alarms and electromagnetic compatibility failures. In order to solve such faults, the project team conducted field tests in and developed a set of electromagnetic environment visualization system based on image recognition algorithm, including image recognition, image processing, electromagnetic signal monitoring, etc., to visually display the electromagnetic environment in key areas of the plant and sort out a complete test and monitoring process.