The invention provides a method for producing blades of a small-sized wind mill. The method comprises the following steps of: A, metrically mixing polypropylene resin and maleic anhydride serving as a grafting modifier according to the weight ratio of 96 to 4; B, dipping glass fibers in 2 percent solution of silicane coupling agent, drying the glass fibers, and cutting the glass fibers into grains of less than or equal to 20mm; C, mixing the grains A and the grains B and adding the mixture into a double-screw extruder to plasticize and extrude the cut grains; D, extruding grains C to form blade section with streamline-shaped cross section according to forming parameters of extrusion temperature of 205+/-5 DEG C and screw rotation speed of 30 to 40r/min<-1>; and E, cutting the section in the step D according to the length-width ratio of 9-19:1. Although the wind energy utilization ratio of the blades with fixed span and zero torsion angle is reduced, the machining method can reduce themanufacturing cost of the blades with the same length to 30 to 40 percent of the original manufacturing cost, so that the method and the blades are absolutely practical for civil small-sized wind mills.