Lightweight, safety, comfort and environmental protection are the main trends of the world automobile industry. Plastic and its composite materials are important automotive materials. Using plastic can not only reduce the quality of parts by about 40%, but also reduce the procurement cost by about 40%. In recent years, the amount of plastic in cars has risen rapidly, and the average amount of plastic in each car has reached 105kg, accounting for about 8%-12% of the total mass of cars. In automotive plastics, polypropylene (PP) with low density, high cost performance, excellent heat resistance, rigidity, corrosion resistance of chemical drugs, easy processing and recycling characteristics in the automobile has been widely used, become the largest amount of automotive plastics, the fastest development of the variety.