The invention relates to an automatic packaging unit for vacuum packaging of an inner bag and an outer bag, which is characterized by comprising a case, a material hopper, a feeding device, a metering device, an inner bag loading device, an outer bag loading device and a vacuum sealing device, wherein the material hopper is fixed on the top of the case; the lower part of the material hopper is provided with the feeding device, the metering device, the inner bag loading device, the outer bag loading device and the vacuum sealing device successively; the unit also comprises an inner bag film supplying device and an inner bag making device which are matched with the inner bag loading device, and an outer bag conveying device which is arranged between the outer bag loading device and the vacuum sealing device; and an outer bag deposited device and an outer bag gaping device are correspondingly arranged on the outer bag conveying device. The automatic packaging unit has reasonable arrangement of the various actuating mechanisms, automatically organic connection of the multiple steps of feeding, metering, bag making, loading of the inner bag and outer bag vacuum sealing and the like and rapid and stable continuous operation, can automatically complete the inner and outer bag vacuum packaging of the flowing solid granule materials such as tealeaf and the like, and greatly improves the automaticity and the production efficiency of the vacuum packaging operation of the inner bag and outer bag.