Hydraulically-driven connecting device

The invention relates to a hydraulically-driven connecting device which is characterized in that a connecting hydraulic cylinder is mounted at the top of a connecting device rack through a hydraulic cylinder tail double-lug seat, and the head of the connecting hydraulic cylinder is connected with a driving clamping block; the driving clamping block and the driven clamping block are respectively and fixedly connected with respective gear shafts, the two gear shafts are respectively and fixedly connected with a sector gear, the two sector gears are mutually meshed and connected, and the driving clamping block is driven to rotate by retraction or extension of a piston rod of a connecting hydraulic cylinder, so that the sector gears drive the driven clamping block to synchronously rotate; and connection or disconnection with the chuck at the head of the connected hydraulic cylinder is realized. Compared with a traditional bolt type connection mode, the connection mode is low in positioning requirement and small i