Vacuum baking bin

A plurality of baking layers are arranged in an inner cavity of a bin body, a chain is wrapped between a head shaft and a tail shaft of each layer, net plates are connected between corresponding chain links of the chains on the two sides respectively, and a hot air chamber of the layer is arranged between the upper net plate and the lower net plate; the outlet of the distributor corresponds to the tail end of the top baking layer, the tail shaft of the next layer is located below the head shaft of the upper layer, the head shaft of the next layer is located below the tail shaft of the upper layer, and so on; the head shafts and the tail shafts are hollow shafts, one end of each head shaft and one end of the bottom-layer tail shaft are connected with a compressed air pipeline through rotary joints, and at least one row of hollow shaft nozzles extending outwards in the radial direction are installed in the length direction of each head shaft and the length direction of the bottom-layer tail shaft respectively.