A vehicle engine cooling fan is disclosed. The invention comprises a tray, a wheel hub and a reinforced rib, and blades. The impeller comprises a tray, a wheel hub, and blades. the blades are airfoil shaped cross section blades, the blades and the wheel hub are formed an integral body, the chord length ratio of the inner and the outer diameters of each blade is between 1:1.1 to 1:1.5, the included angle of each cross section gravity line and the radial straight line of the blades is between 5 degrees to 25 degrees, the projection distance on the rotating axle of each cross section gravity line of the blades is controlled between 2% to 8% of the impeller diameter, the projection distance presents a space twisted shape, and the arc transition is adopted at the connection of the blade and the wheel hub. The reinforced rib is a honeycomb-shaped reinforced rib, and the honeycomb-shaped reinforced rib is of a regular hexagon hexagonal shape. The blades and the diversion ring are connected together. The efficiency is high, the noise is small, the slip flow can not easily occur at the tail part, and the service life is long.