Abstract: Rigid polyurethane foam has several advantages, such as low density, electrical insulation, heat insulation, and wave-transsion. In this paper, it was introduced the development of radome with good dielectric properties, which was made of high density polyurethane foamed plastic. Through the research about polyurethane foamed plastic formulation, weather protection coat and radome forming process, we developed the radome with high strength, fine dielectric property and good weather resistance, which could meet the needs of the product.