The utility model relates to a monitoring device for the running of a plurality of main transformers of an unattended substation. The device consists of a camera A, a camera B, a camera C, a camera D, a camera E, a universal serial bus (USB) high-speed wire connector and an Internet interface, and is characterized in that: the cameras A, B, C, D and E are connected with the USB high-speed wire connector respectively; and the USB high-speed wire connector is connected with the Internet interface. By the technical scheme, the utility model has the advantages that: the monitoring device is easy to operate and convenient to use.