The invention belongs to the field of beef processing, and in particular, discloses a marinated beef tendon-breaking device which comprises a rack, a hopper, stand pipes and a marinating water pot; the rack is fixed on the ground; the hopper is fixed on the rack, the bottom of the hopper is provided with a roller couple, the roller couple comprises a left roller and a right roller, meat loosening needles are evenly arranged on the left roller and the right roller, a gap is left between the left roller and the right roller, and the left roller and the right roller are internally respectively provided with a left rotating shaft and a right rotating shaft; the stand pipes comprise a left stand pipe and a right stand pipe which are in mirror symmetry, a cross pipe communicating the left stand pipe and the right stand pipe are arranged between the left stand pipe and the right stand pipe, the left stand pipe and the right stand pipe are respectively arranged at both sides of the hopper and are both fixed on the rack, and the bottom of the left stand pipe is provided with a left cylinder sleeve; the marinating water pot is located above the stand pipes, and a connection pipe is arranged between the marinating water pot and the left stand pipe or the right stand pipe. For the technical problem of unstable pressure of a needle plate on beef, the marinated beef tendon-breaking device is provided.