Box-type substation intelligent monitoring device (power RTU) is used to solve the problem of centralized monitoring of multiple circuits in power distribution rooms, ring network cabinets and opening and closing stations, etc. Using fiber optic, wireless, wired and other communication means and automation control technology, it can collect signals such as through, self-closing voltage, current, switch status, temperature, air pressure, etc. from high and low voltage cabinets in railway intelligent box transformers, control high and low voltage switches, support multiple protection as well as data upload, and realize automation functions such as sub-station and master station cooperation of distribution automation system as well as collecting, monitoring, fault judgment and isolation of operation status of multiple distribution lines.