The invention discloses a centrifugal air compressor including an air compressor body. A placement table is arranged on the air compressor body. A compression cabin and an air intake structure are respectively installed on two sides of the top of the placement table. A mounting chamber is formed inside the compression cabin. A cooling channel is formed in an interlayer between the mounting chamberand the compression cabin. A plurality of butt joint projections are fixedly installed on the inner walls of two sides of the mounting chamber. A first butt joint plate and a second butt joint plateare arranged on the compression cabin and the air intake structure, wherein a first joint groove, a second joint groove and a third joint groove in the first butt joint plate are connected to a firstconnector, a second connector and a third connector on the second butt joint plate in a one-to-one manner. During use, by pushing a placement box on the air intake structure by hands, the first butt joint plate and the second butt joint plate are separated, so that the compression cabin and the air intake structure are separated. Due to the structure, the centrifugal air compressor has conveniencein cleaning and replacement in later period and is convenient to arrange and transport.