A wind wheel including a first air plate, a second air plate, and a plurality of blades disposed between the first air plate and the second air plate. The first air plate includes a central part and an air inlet disposed in the central part; each two adjacent blades form an air duct. The plurality of blades each includes an inlet section next to the air inlet, an intermediate section, and an outlet section. The thickness of the intermediate section is greater than the thickness of the inlet section and the thickness of the outlet section.