The invention discloses an electrical system monitoring apparatus of a box-type transformer substation, and belongs to the field of transformer substations. According to the invention, the apparatus aims at overcoming lack of monitoring internal electrical systems of current box-type transformer substations. The apparatus herein includes two lead screws, a transverse exhibition pole, a LED light strip, a plurality of cameras and an electrical system inspection unit. The two lead screws are disposed in parallel on two sides of a door inside a box body. The transverse exhibition pole is horizontally disposed between the two lead screws. The two ends of the transverse exhibition pole are in separate and rotary connection to the two lead screws through nuts. A motor M drives the two lead screws in synchronization. The transverse exhibition pole is evenly provided with the plurality of cameras on the side wall thereof facing the inside of the box body. The side wall is provided with the LED light strip thereon. The transverse exhibition pole drives the cameras to move up and down in a reciprocating manner so as to monitor all electrical elements inside the box body in a scanning manner. A photographing light source is provided by the LED light strip which is disposed on the transverse exhibition pole. The start and termination of the reciprocating operation is controlled by a remote monitoring center which sends commands to a remote switch.