Corrugated steel sheet can directly bear the load of the roof. Roof panels are located on the roof of a house and are generally made of metals such as alumin.um, magnesium and manganese or alloys. After the roof panels are assembled on the sloping beams of the roof wall, the wing panels are lapped to cover the vertical joints that prevent the light from appearing in multiple single box roof panels, forming a sloped roof with good integrity. Aluminum-magnesium-manganese alloy for roofing and exterior wall generally adopts pre-roll coating (Coil Coated) process, which has the advantages of good color difference control, uniform paint film, high quality stability and environmental protection. The coating type generally uses PVDF fluorocarbon paint which contains more than 70% of fluorocarbon resin.