The invention discloses a full-automatic cut-off machine which comprises a base, a driving device, a cutting die, a first cutting knife, a second cutting knife, a rack and a controller, wherein on the basis of the user direction, thedriving device comprises a fixed end and a driving end; the driving end can linearly slide relative to the fixed end; the fixed end of the driving device and the cutting die are fixed on the base; the first cutting knife and the second cutting knife are fixed on the driving end of the driving device and respectively prop against both sides of the cutting die; the first cutting knife and the second cutting knife can move relative to the cutting die in the cutting die direction; the rack is demountably fixed on the cutting die; the cutting die is provided with afixing device which can fix a product to be processed; the controller is fixed on the base and can control the driving end of the driving device to move; and when in use, the cutting die produces shearing force with the slideable first cutting knife and the second cutting knife, thereby achieving the shearing effect. The invention has the advantages of simple structure, safe use, convenient operation, high production efficiency and low fraction defective.