The invention discloses a circulating-flow hot air drying tower which is composed of a preheating storehouse, 2-8 drying storehouses, a cooling storehouse, vacuum heat conduction and heat dissipation devices, discharge valves, circulating-flow air exchanging and exhausting devices, heat conduction pipes, a feed port, a discharge port and a support. The support is sequentially and fixedly provided with the cooling storehouse, the drying storehouse and the preheating storehouse in a supporting mode from bottom to top; the vacuum heat conduction and heat dissipation devices and the circulating-flow air exchanging and exhausting devices are installed in the preheating storehouse and the drying storehouses; the circulating-flow air exchanging and exhausting devices are installed in the cooling storehouses; the vacuum heat conduction and heat dissipation devices directly perform heat conduction, heating and heat dissipation in the storehouses; air outside the tower sequentially enters the cooling storehouse, the drying storehouses and the preheating storehouse and is lastly exhausted out of the tower by draught fans in the drying storehouses and the preheating storehouse. Through air exchanging and exhausting of the circulating-flow air exchanging and exhausting devices, hot air in air storehouses of the drying storehouses can be repeatedly circulated, exchanged and used, the material quality is guaranteed through the controllable drying temperature, and energy-conservation and emission-reduction green drying is achieved.