Packaging device for folding long side face of cigarette packet label paper and folding packaging method

The packaging device comprises a synchronous belt, the front long side face of the label paper of the cigarette packet is unfolded and located on the front side of the synchronous belt, the rear long side face of the label paper of the cigarette packet is unfolded and located on the rear side of the synchronous belt, and cold glue nozzles are arranged on the front side and the rear side of the right portion of the synchronous belt correspondingly. Hot glue nozzles are arranged on the front side and the rear side of the left portion of the synchronous belt respectively, first vertical pushing handles are arranged on the front side and the rear side of the synchronous belt on the left sides of the hot glue nozzles respectively, a rotating disc with a plurality of mold boxes is arranged on the left rear side of the synchronous belt, and the two first vertical pushing handles are matched to push cigarette packets sprayed with glue into the mold boxes rotating to the position above the synchronous belt; a vertical