The invention provides a low clearance bridge image acquisition device and effectively solves the problems that the existing equipment is difficult to acquire the image data of the bottom of a low clearance bridge, the data is inaccurate and the operation is inconvenient, and the like. The device includes a controller and an image acquisition device, and the image acquisition device comprises a base, a shell which is fixed on the base, and a camera which is fixed on the shell. The low clearance bridge image acquisition device is characterized in that the connection transfer between a locking cam in a chuck and a rotating disc or the shell achieves sliding up and down or rotation of the rotating disc, various movements are achieved by a set of mechanism, the number of mechanisms in equipment is greatly reduced, the operation is simplified, the overall mechanism is fixed by friction between the locking cam and the rotating disc or the shell, the post-maintenance cost is low, and when theequipment lock is invalid, only the locking cam is required to be replaced, so that the maintenance cost is saved, and the maintenance efficiency is improved.