An automatic page-turning device is formed by a desk, a supporting plate, a stopping block, an electromagnet, a book, a first position switch, a photoelectric switch, a sliding rail, a motor support, a motor, a driving gear, a gear shaft, a bearing, a rotating rod, a second position switch, an extensible rod, a flat sucking disk and a supporting rod; the supporting plate is connected with the desk through a rotating shaft; the supporting rod and the desk are hinged together; the motor support is fixed on the rear portion of the supporting plate; the motor is fixed above the motor support; the driving gear is connected onto an output shaft of the motor; the gear shaft is fixed in front of the motor support through the bearing; the sliding rail is fixed on the desk and located in front of the motor support; one end of the rotating shaft is connected with an output end of the gear shaft and the other spherical end of the rotating shaft is located in the sliding rail; one end of the extensible rod is fixed on the rotating rod through a bolt and the other end of the extensible rod is connected with the flat sucking disk; the stopping block is fixed on the front portion of the supporting plate; the electromagnet is placed on the supporting plate and located in front of the book. According to the automatic page-turning device, the automatic page-turning function can be achieved.