The utility model discloses an automatic case-blank feeding device for case packers, which is composed of a rack, an input roller table, an output roller table, a main drive lifting device, a feed bin, a suction-cup gripping device and an electronic control unit, wherein the input roller table, the output roller table, the main drive lifting device, the feed bin, the suction-cup gripping device and the electronic control unit are arranged on the rack; the rack is divided into a left part and a right part, the left part is an input/output part and divided into an upper layer and a lower layer, the input roller table is arranged at the upper layer, and the output roller table is arranged at the lower layer; and the right part is provided with the main drive lifting device and the suction-cup gripping device, and the devices are controlled to operate by the electronic control unit. The automatic case-blank feeding device disclosed by the utility model has the characteristics of reasonable structure, simple operation, energy saving, high efficiency, accurate control, and capability of automatic feeding, and the like. Especially, because a point-to-point control and circulating control mode is adopted, an automatic blank feeding technique for feed bins of case packers is realized, the technical problem existing in the feeding of case packers is solved, the labor intensity of operators is reduced, and the application quality of case blanks is ensured, therefore, the automatic case-blank feeding device is a most ideal special supporting device for the automatic feeding of various case blanks.