A vacuum packaging system includes a vacuum room, a delivery apparatus, a discharge device, a second heating apparatus. The delivery apparatus transport the pre-packaged container into the vacuum room. The discharge device discharges a sealing material to seal an exhaust through hole of the pre-packaged container. The discharge device includes a vessel configured for containing sealing material, a transport pipeline, a first heating, and a controlling element. The first heating apparatus softens the sealing material into viscous liquid. The second heating apparatus is mounted on the inner wall of the vacuum room between the second hatch and the transport pipeline.