An automatic disc eject device for a disc-loading tray of an optical disc drive comprises: a disc-loading frame, a movable disc-loading piece and a pivot. The movable disc-loading piece is connected to the disc-loading frame by a pivot to form a disc-loading tray. When ejecting the disc, the movable disc-loading piece rotates downward about the pivot to allow the optical disc to fall by gravity without having to take the disc out of the disc-loading tray manually. Therefore, the automatic disc eject device can improve the disc-burning efficiency and speed, reduce the labor consumption and improve the productivity.