As inorganic filler, aluminum hydroxide is very different from polymer material in physical morphology and chemical structure, and their affinity is very poor. Through reasonable organic modification of aluminum hydroxide, the compatibility between aluminum hydroxide and polymer materials can be greatly improved. Increase the affinity between aluminum hydroxide and resin, and improve the physical and mechanical properties; Increase the content of aluminum hydroxide, increase the flame retardancy and reduce the cost of products; Increase resin processing fluidity and improve processing performance; Reduce the surface moisture absorption of aluminum hydroxide, and improve the electrical properties of flame retardant products. Common coupling agents include silane coupling agent, titanate, stearic acid, etc.