A baffle-type one-way overspeed cut-off valve comprises a valve body, a valve cover, a valve plate, a glass window and a reset handle. The baffle-type one-way overspeed cut-off valve is characterized in that a corner bracket formed by a floorstand and a baseplate is arranged inside the valve body, a testing shifting fork is hinged on the floorstand, and two, three or four dry reed connection points are arranged on the floorstand. An adjustable plate hinged on the baseplate is supported on the testing shifting fork, positions corresponding to two dry reed connection points below the adjustable plate are respectively provided with a magnet, a tension spring screw rod mechanism is arranged between the adjustable plate and the baseplate, and the valve plate is fixed on the upper side of the adjustable plate. A reset rotating shaft is arranged on the end position of the oil outlet of the valve body, the reset handle is fixed at the shaft end of the reset rotating shaft outside the valve body, and a reset pusher dog is arranged on the reset rotating shaft inside the valve body. Two turning-over covers are arranged on the valve cover, and the valve cover and the two turning-over covers respectively form a wire connecting cabin and a detecting exhausting cabin independently. The baffle-type one-way overspeed cut-off valve has the advantages of being small in the setting error of flow velocity, strong in anti-seismic property, small in malfunction probability, good in sealing, long in service life and the like.