Abstract: Abstract: Due to the strong electromagnetic interference sources present in substations, the power modules used on camera poles are susceptible to electromagnetic interference, which affects their normal operating state, leading to frequent abnormalities in the equipment on site and reducing the availability and reliability of the image surveillance system. In response to the above issues, the author has researched and proposed a power module solution that is suitable for the complex electromagnetic environment of substations. The author has also explored several common electromagnetic interference methods and paths within the station, calculated the transmission paths and intensities of electromagnetic interference in the power supply lines, and proposed an integrated common-mode composite filtering + isolation shielding anti-interference design scheme. Effectiveness verification tests have been conducted, and all performance indicators meet engineering requirements, providing a reference for the design of power reliability in substation surveillance systems.