The 27.5kV mobile high-voltage room is suitable for the overhaul of traction substations, open and closed stations and other power supply and substation facilities of existing operating lines; it integrates high-voltage electrical equipment, comprehensive automation systems and auxiliary monitoring systems in a movable, closed metal box through system integration and primary and secondary fusion technologies, which can realize the functions of high-voltage rooms and control rooms of existing traction substations and serve as a substitute for high-voltage rooms and control rooms during the implementation of reconstruction projects. The mobile high-voltage chamber has a building block structure, which can be flexibly combined according to the application requirements and has various wiring forms.