Iron oxide pigments are a type of pigment that has good dispersion, excellent light and weather resistance. Iron oxide pigments mainly refer to four types of pigments based on iron oxides: iron oxide red, iron yellow, iron black, and iron brown. Among them, iron oxide red is the main one (accounting for about 50% of iron oxide pigments), and mica iron oxide used as a rust-proof pigment and magnetic iron oxide used as a magnetic recording material also belong to the category of iron oxide pigments. Iron oxide is the second largest inorganic pigment after titanium white and the largest inorganic pigment in color. In the total consumption of iron oxide pigments, more than 70% are prepared by chemical synthesis, which are called synthetic iron oxide. Synthetic iron oxide has high synthesis purity, uniform and regular particle size, wide color spectrum, rich color, low price, non-toxicity, excellent coloration and application performance, and has the performance of absorbing ultraviolet rays, etc., therefore, it is widely used in the fields of building materials, coatings, plastics, electronics, medicine, rubber, ceramics, inks, magnetic materials, papermaking, etc.