The invention discloses a novel automatic box opening machine which comprises a box plate conveying mechanism, a box taking, folding and feeding mechanism, a sealed box clamping belt, an adhesive tape box-sealing mechanism and an electrical control mechanism; the box taking, folding and feeding mechanism comprises a box plate taking mechanism, a box plate opening mechanism and a large sheet folding mechanism; the box plate conveying mechanism comprises a bottom supporting frame, a lifting mechanism fixedly arranged above the bottom supporting frame, a lifting framework fixedly mounted above the lifting mechanism, a chain conveying mechanism arranged on the lifting framework, an adjustable box plate protecting mechanism arranged above the lifting framework, and an automatic box feeding and pushing mechanism arranged above the lifting framework; and the box plate opening mechanism comprises a box plate opening mechanism mounting plate, a small sheet folding structure, a box opening and pushing mechanism and a regulating lead screw. According to the novel automatic box opening machine disclosed by the invention, each independent structure is controlled, the mechanisms are clear, and control and follow-up maintenance are convenient, so that the integral structure realizes automatic box opening, is high in working efficiency and is suitable for opening box plates of different sizes.