The JIS G 3322-2012 standard specifies the technical requirements for pre-film hot-dip 55% Al-Zinc alloy coated steel sheets and coils. The standard applies to steel coated with Al-Zinc alloy layer and pre-coated, mainly used for external components in fields such as construction, automotive and home appliances. The standard describes in detail the composition of the coating, performance requirements, test methods and surface preparation techniques to ensure that it has good corrosion resistance, weathering resistance and anti-pollution ability. In addition, the material thickness, coating adhesion, scratch resistance and other key performance indicators are also specified to guarantee the long-term Stability and Reliability of the product in practical applications. Through the implementation of this standard, it helps to improve the mass and application effect of coated steel.