The fan blades include: the inner edge side, the inner edge side is connected with the periphery of the central part of the fan wheel, the outer edge side is the fan blade, the wind side is located at the front end of the fan blade, and the tail end of the fan blade in the direction of rotation, which is characterized in that the outer end of the upwind side is located on the upwind side in the direction of rotation in the front of the inner end, and the outer end of the upwind side is contacted in the direction of rotation