A centrifugal impeller including a wheel cover, a wheel disc, and a plurality of blades disposed between the wheel cover and the wheel disc. The wheel cover and the wheel disc each includes a sheet metal, and the plurality of blades includes a composite material. The wheel cover includes an air inlet. The wheel disc includes a central part and a motor mounting base disposed on the central part. Every two adjacent blades form an air channel including an air outlet. The plurality of blades each includes a metal frame, and a plastic shell disposed on the metal frame. Two ends of the metal frame are connected to the wheel cover and the wheel disc, respectively. The metal frame is integrated with the plastic shell through injection molding. The plastic shell is wrapped around at least a part of the metal frame.