The utility model relates to a novel burning furnace is baked over a slow fire in gyration of double -deck passageway continuous type. It comprises outer barrel and interior barrel to bake the burning furnace barrel over a slow fire, be equipped with the baffle in outer barrel and the interior barrel passageway, the flight, it divide into the feed end to bake the burning furnace barrel over a slow fire, the section heaies up, constant temperature section and discharge end, the feed end sets up the supplementary feeding of spiral guide flight, it has transmission to bake burning furnace barrel outside over a slow fire, braced system, the barrel that bakes burning furnace intensification section and constant temperature section over a slow fire has the heat preservation of heating furnace outward, it is connected with the feeder to bake burning furnace barrel feed end over a slow fire, sealing ring structure is adopted to the junction, the inside and outside barrel of discharge end is connected with the discharger respectively, seal structure is adopted to the junction. The utility model discloses replace the calcination mode of original single channel continuous type rotary furnace, the mode messenger equipment of the inside and outside double -layer barrel body calcination has the ability of two kinds of calcination conditions simultaneously, has increased calcination efficiency. This rotary furnace can be by the wide application in the industrial production of the graininess catalyst and the carrier calcination.