Iron oxide green (Fe2O3 · H2O) is a chemical with very stable chemical properties. It is widely used. It is mainly used in paint, construction industry, plastics, building materials, etc. to color products and increase product beauty. At the same time, due to its stable chemical properties, it also has relatively objective protection for the articles themselves, which is equivalent to putting a layer of protective clothing on the products, so it is recognized by the majority of users.