The invention discloses a cable trench automatic inspection device. The cable trench automatic inspection device includes a mobile chassis; a tracked bogie is adopted as the mobile chassis; the body of the bogie is provided with a temperature and humidity sensor, a path detection camera, a data storage device and a power source supplying power for the whole automatic inspection device; the front end of the body of the bogie is provided with a lighting lamp; the body of the bogie is vertically provided with an electric push rod; the upper part of the electric push rod is provided with a holder; an imaging device is installed on the holder; two holder motors are installed in the holder; the upper part of the electric push rod is provided with a synchronous toothed wheel; the holder motors are in engaging transmission with the synchronous toothed wheel through a reduction gear, so that the holder can be driven to rotate freely in a horizontal direction; the state of a cable in a cable trench can be detected through various kinds of sensors, and the temperature and humidity of the cable trench can be detected by means of the temperature and humidity sensor, and therefore, the environmental state of the cable trench can be judged, and thus, problems such as damage to the cable caused by over-temperature of the cable in an operating process can be solved.