The invention discloses a numerical control automatic discharge device of a longitudinal dividing and cutting machine. The numerical control automatic discharge device comprises a first device, a second device and a third device. According to the first device, a discharge device base is fixed to a dividing and cutting machine base and fixedly connected with a driving motor base, a linear guide rail on the upper portion is connected to the discharge device base through screws, the end, close to a motor, of a ball screw is provided with a ball screw synchronous pulley, and a driving motor synchronous pulley and the ball screw synchronous pulley are connected through a synchronous belt. According to the second device, a discharge frame rotating stand column and a base are connected together through a bearing, a discharge overturning arm and a discharge overturning arm rotating shaft are fastened together through screws, the discharge overturning arm rotating shaft is connected with the discharge frame rotating stand column through a bearing, and a discharge shaft A and a discharge shaft B are fastened to the two sides of the discharge overturning arm through screws. According to the third device, an air expansion head screw is fastened to a four-shaft mechanical hand. The numerical control automatic discharge device has the functions of being reasonable in structure, reducing space, achieving full numerical control programming control, improving working efficiency, reducing the manual labor intensity and the like.