The invention relates to an air sorting device, which belongs to the field of air sorting technology for chemical material. The 
system comprises an 
air blower (2), an air register (3), an air sorting chamber (4), a 
relay drum (5), a 
settling centrifuge (6), an input material conveyor (1), a heavy material output conveyor (8), a light material output conveyor (7), an air return 
pipe (9), a stand, a dust remover and a 
control system. The 
settling centrifuge (6) includes a transmission device (12), a pin wheel (13), a ring grate (17) and a bar grate (18). The 
system adopts the 
relay drum (5) to reduce the air active section to compensate for the short migration distance of light material under the action of air force, thus obviating the secondary falling back and mixing of the sorted light material. Additionally, an intensely centrifugal air flow is used for separating particles and dust, and high-speed rotation energy can be converted into 
dynamic pressure by discharging air through a 
volute. The 
system has the advantages of compact structure, less occupied area, short 
pipe, less resistance, strong air power of the air sorting chamber, high sorting efficiency and stable and reliableoperation. The air sorting 
unit device can be used for sorting oversize plastics of 
urban life garbage and for sorting other industrial 
mixed materials.