The coated steel sheet is a metal sheet such as a cold-rolled steel sheet or a galvanized steel sheet as a substrate, which undergoes surface pretreatment (degreasing, cleaning, chemical conversion treatment), and is coated with paint in a continuous method (roller coating method), after baking and cooling. products made. The coated steel plate has light weight, beautiful appearance and good corrosion resistance, and can be directly processed. It provides a new type of raw material for the construction industry, shipbuilding industry, vehicle manufacturing industry, home appliance industry, electrical industry, etc., and plays a role in replacing steel with steel. Good effects such as wood, efficient construction, energy saving, and pollution prevention.