Centrifugal fan

The utility model relates to a centrifugal fan. The centrifugal fan comprises a shell and a fan blade module. Wherein the shell comprises a lower cover, a side wall and an upper cover, two ends of the side wall are respectively connected with the lower cover and the upper cover, and the lower cover, the side wall and the upper cover define an internal space. The lower cover is provided with a plurality of lower air inlets. The fan blade module is arranged in the internal space and comprises a hub and a plurality of fan blades. The hub is rotatably arranged on the lower cover. The fan blades are arranged on the periphery of the hub in a surrounding mode. The lower air inlets are located around the hub, and each lower air inlet is provided with an outer edge relative to the rotating axis of the hub. At least one of the two opposite ends of at least one of the lower air inlets is provided with a protruding part at the position corresponding to the outer edge of at least one of the two opposite ends of at least o