The surface layer of the coated steel plate is not easy to be corroded, and the high weather-resistant PMMA/ASA alloy co-extruded anti-corrosion and weather-resistant film on the upper surface can ensure that the color will not fade for a long time, with good corrosion resistance and strong aging resistance. The hardness of the material is high, and the weight per unit volume is the lightest among metal materials. The coated steel plate has the advantages of both the metal plate and the engineering resin material. It not only has the advantages of high mechanical strength, good toughness, and easy processing and forming of the metal plate, but also has the good coloring, decoration and resistance of the polymer coating material. Corrosive, can be easily punched, bent, deep-drawn, welded and other processing, the products made are practical, easy to process, durable, and corrosion-resistant. The coated steel plate can achieve a good anti-corrosion effect on common corrosive chemicals such as sulfur dioxide, sodium hydroxide, ammonia, heptane, sodium oxide, hyaluronic hydroxide and other corrosive chemicals, and can improve the building The service life of the material can save time, worry and effort for users.