In order to further strengthen the flow, mass transfer and mixing performance of the air lift loop reactor, a new type of annular air lift loop reactor was designed. The reactor is made of plexiglass. Outer tube height is 1 800 mm, the inner diameter of 90 mm, the length of the draft tube is 1 600 mm, the diameter of the main body is 50 mm, and the draft tube is attached with a number of groups spiral fins. when the superficial gas velocity is in the range of 0.37~2.59 cm/s, in the effect of bottom clearance, solid loading and different materials on the distributor of gas holdup in the reactor. The results show that the apparent gas velocity under the same conditions, with the increase of superficial gas velocity, rising area of local gas holdup increases; solid loading increases, rising area of local phase holdup increases; the bottom gap becomes larger, rate becomes larger with the local gas under low gas velocity; high gas velocity, gas the rate of change. At low superficial gas velocity, local gas holdup was lower than that of polymer materials with microporous local gas distributor; when the superficial gas velocity is high, the result is opposite.