Cooling fan of air blower

A cooling fan of an air blower comprises an upper cover plate, a bottom plate, a side plate and an impeller, and is characterized in that the impeller is arranged in a fan shell composed of the upper cover plate, the bottom plate and the side plate, no side plate is arranged on one face between the upper cover plate and the bottom plate, the hollowed-out portion is an air outlet of the fan, and an air inlet is formed in the portion, opposite to the impeller, of the upper cover plate. A wedge-shaped air guide structure is arranged on the related side face and is of an acute angle structure protruding outwards along the vertical side face. According to the cooling fan of the air blower, due to the fact that the wedge-shaped structures are designed on the side plates, air flow is guided to flow from the side faces to the air inlets in the top faces along the oblique angles, the problem that the air flow is blocked on the side faces to generate turbulent flow is solved, the air inlet effect is better, and the coo