The invention discloses a polypropylene composite material and a preparation method thereof, wherein the material includes, by weight, (a) 40-85% of polypropylene resin, (b) 5-30% of a toughening agent, (c) 5-40% of a filling material, (d) 0.1-1% of a composite antioxidant, and (e) 0.1-1% of a processing aid. The preparation method includes the steps of (1) weighing the material according to the weight ratio of 40-85% of the polypropylene resin, 5-30% of the toughening agent, 5-40% of the inorganic material, 0.1-1% of the composite antioxidant, and 0.1-1% of the processing aid; (2) mixing the raw materials in a high-speed mixer uniformly; and (3) performing extrusion in a double-screw extruder to obtain a blended substance. The polypropylene composite material is excellent in anti-impact performance, is high in toughness at normal and low temperatures, is excellent in notch impact strength and is excellent in heat resistance and rigidity.