Fan wheel with sickle-shaped fan blades and centrifugal fan with fan wheel

The fan wheel comprises a hub and a plurality of fan blades, the fan blades are sequentially arranged at intervals around the radial periphery of the hub, each fan blade is mainly formed by connecting a first sweep-forward section and a second sweep-forward section, each first sweep-forward section is connected with the hub, each second sweep-forward section is connected with the hub, and each second sweep-forward section is connected with the hub. The second sweep-forward sections extend in the direction away from the hub, the connecting points are located between the first sweep-forward sections and the second sweep-forward sections connected with the first sweep-forward sections respectively, and the flow channels are formed between the adjacent fan blades respectively. And the width of each flow channel between the adjacent second sweep-forward sections is gradually reduced from two adjacent connection points to the direction of the tail end, far away from the hub, of each second sweep-forward section. By