Circular current airlift fermentor

The utility model belongs to the microbiological ferment equipment field, and relates to microbiological submerged ferment production equipment. The utility model relates to a circulating gas lift fermentation tank, comprising a tank body, and is characterized in that a guide shell is mounted in the tank body, an air inlet pipe is arranged at a lower port of the guide shell, an axial-flow type paddle is mounted on an upper portion of the tank body and at an upper port of the guide shell, and the rotation of the paddle can lift the culture liquid in the tank. When the culture liquid is high in concentration in working, the circulating gas lift fermentation tank in the utility model can assist the culture liquid to circulate and flow, which leads the culture liquid to more completely stir and dissolve oxygen, thereby substantially shortening the ferment period.