The invention discloses a low-noise and efficient cooling axial flow fan of a central air conditioner outdoor unit. The low-noise and efficient cooling axial flow fan comprises an air duct, a motor support, a motor, a hub a plurality of blades which are fixed on the hub, wherein the motor support is arranged above the air duct, the motor is arranged at the center of the motor support, and the hub is connected with a motor rotary shaft. The hub comprises a hub inner lining panel and a shaft sleeve which is connected to the center of the hub inner lining panel in a welded mode; the shaft sleeve is matched with the motor rotary shaft; the periphery of the hub inner lining panel extends to form a plurality of hub connection boards which are evenly distributed with the shaft sleeve as the center; each hub connection board is provided with a plurality of thread hole; each hub connection board is twisted in the reverse direction from the two side edges of the primary portion where the hub inner lining panel extends. The low-noise and efficient cooling axial flow fan of the central air conditioner outdoor unit lowers vortex loss of the wall surface by decreasing the hub ratio, and decreases flowing speed of air flow, thereby effectively lowering noises caused by the air flow.