The ultra-white composite layer on the surface of the waterproof and anti-corrosion board realizes the passive reflection of radiation in the building during the day, which is also an important and practical step to keep the building cool. The surface of the waterproof and anti-corrosion board can reflect sunlight and radiate heat into the air, so that the indoor temperature is lower than the ambient temperature. This can help lower indoor temperatures, reduce air conditioning use and carbon dioxide emissions, and reduce energy consumption.