PU paint is a relatively common type of paint, which can be divided into two-component PU paint and single-component PU paint. Two-component PU coatings are generally composed of isocyanate prepolymers (also called low-molecular-weight urethane polymers) and hydroxyl-containing resins, usually called curing agent component and main agent component. There are many varieties of this type of coatings, and the application range is also very wide. According to the different hydroxyl-containing components, it can be divided into acrylic polyurethane, alkyd polyurethane, polyester polyurethane, polyether polyurethane, epoxy polyurethane and other varieties. Generally, it has good mechanical properties, higher solid content, and better performance in all aspects. It is a kind of paint variety with great development prospects. The main application areas are wood coatings, automotive repair coatings, anti-corrosion coatings, floor coatings, electronic coatings, special coatings, etc.