Improved cofferdam device

The utility model relates to the technical field of cofferdam devices, in particular to an improved cofferdam device which comprises a bottom plate and a cofferdam body, the inner wall of the inner side of the cofferdam body is in threaded connection with a supporting plate through a plurality of bolts, a fixing device is installed above the supporting plate, and a connecting device is installed above the front end face of the cofferdam body. Two cofferdam bodies can be attached together, a concave plate is installed on the two cofferdam bodies, then a supporting plate and the cofferdam bodies are fixed through bolts, a two-way screw is rotated, the two-way screw is matched with a stop lever to drive a second vertical plate and a baffle to move, and the baffle enters a groove of a third vertical plate; in this way, the third vertical plate can be fixed through the baffle, so that the concave plate is fixed to the cofferdam bodies, the two cofferdam bodies can be connected and fixed, even if the cofferdam bodi