The invention relates to a device for pasting a cover paper on a paperboard, which adopts a vertical paper delivery way. The device for pasting the cover paper on the paperboard comprises a paperboard conveying mechanism and a cover paper conveying mechanism, and the paperboard conveying mechanism is located above the cover paper conveying mechanism. The device is characterized in that the conveying surface of the paperboard conveying mechanism is downwards inclined; a limiting part is arranged above the paperboard conveying mechanism; the bottom surface of the limiting part is a limiting surface which is downwards inclined; a paperboard sucking mechanism is arranged above the cover paper conveying mechanism; the paperboard sucking mechanism comprises a suction nozzle and a rotating arm, the suction nozzle is mounted on the rotating arm, is connected with an air source and faces to a paperboard feeding direction, and the rotating arm is mounted on a rotating shaft which is driven by and connected with a rotating arm power source; and one side of the limiting part is provided with a locating part, and the locating part is provided with a photoelectric eye facing to the feeding side. By using the device for pasting the cover paper on the paperboard, scratches caused by paper delivery friction can be avoided; and compared with a drawing-out paper delivery way, the structure has the advantages that the paper feeding speed is higher, and the book case processing efficiency is higher.