The invention provides a rotary feeder sealed through air curtains. The rotary feeder comprises a cambered impeller rotor, a shell body, a pressure limiting valve, a feeding inlet, a discharging outlet, rotating joints, externally-arranged bearings, big end caps, small end caps and conical sleeves. The cambered impeller rotor is of a hollow structure, and is provided with cambered plates evenly distributed along the circumference. An axial clearance taken as an airflow channel for the axial sealing air curtain is arranged between the tops of every two adjacent cambered plates. Annular clearances taken as airflow channels for the end face sealing air curtains are arranged between inner side plates and outer side plates. A hollow shaft, the cambered plates, the inner side plates and the outer side plates are connected into a whole. The cambered impeller rotor is detachably connected through the conical sleeves, studs, nuts, annular gaskets, arc-shaped grooves and the like. Compared with an existing feeder, the closed air curtains formed in the rotary feeder are good in sealing effect. The rotor does not make contact with the inner surface of the shell body, and the rotor is free of abrasion, so that the service life of parts and components is long. The rotor is flexible in operation and convenient to disassemble and clean. The rotary feeder can be taken as a non-contact rotary sealed feeding device which is capable of achieving continuous conveyance of materials.