It is a new type of building decoration material made through a composite process, consisting of two thin aluminum alloy sheets as the panels and a plastic core layer (such as polyethylene, etc.) sandwiched in between. It combines the strength and corrosion resistance of aluminum alloy with the lightweight characteristics of plastic, and has advantages such as light weight, good rigidity, strong decorativeness (can be processed into various colors or textures), and easy installation. It is widely used in fields such as building exterior wall decoration, interior wall decoration, and billboard production.