The corrosion process of color steel tile roof is a complex chemical reaction process. We will find that rust is usually reddish brown, mainly composed of iron oxide hydrate and iron hydroxide. The rust on the surface of color steel tile seems to be attached to the substrate, but it is not firmly attached to the substrate, or there are tiny holes in the middle, and oxygen and water vapor in the air directly contact the substrate through the holes, which eventually leads to the rust of all the substrates of color steel tile.