This paper proposes a scheme of space electromagnetic environment imaging monitoring system for nuclear power plant based on shared database technology. Firstly, the spectral data of field programmable gate array is collected and processed. In this method, the color query list of multi-wave bands is established to realize the color display of images with different wave bands. Real-time feedback of spectral data of magnetic field environment is realized by using shared database technology. The terminal display control system displays the electromagnetic spectrum distribution in space of the measured nuclear power plant in real time and intuitively in the form of spectral diagram and radiation heat map. The monitoring of electromagnetic spectrum extends from surface to stereo. The simulation results show that the simulation image can not only show the spatial distribution of each frequency band in the electromagnetic environment, but also reflect the common influence of each frequency band. This allows users to better understand their electromagnetic environment.