The invention relates to the technical field of cable trench cover plate control devices, and provides an intelligent ventilating device of a cable trench cover plate. The device comprises a cable trench body, a movable cover plate, linear guide rails, a rack, a gear and a power driving device. At least one movable cover plate is horizontally distributed at the upper part of the cable trench body with an upward opening. The bottom of each movable cover plate and the top of the corresponding cable trench body are arranged together through two linear guide rails which can reciprocate back and forth. Two linear guide rails are respectively located at the bottom of the corresponding movable cover plate. According to the invention, the power driving device is controlled to open and close the movable cover plate, which is easy and labor-saving and saves time and effort; an automatic control unit can automatically control opening and closing of the movable cover plate and a fan; remote control is realized through a key control unit and a command sending unit; a cable is effectively prevented from damp, grounding and rain pouring; operation and maintenance costs are reduced; and the safety factor is improved.