Compared with single part spraying or brushing on the surface of forming metal, the coating quality of color-coated steel plate is more uniform, stable and ideal. Pre-painted steel plate is characterized of excellent decoration, mold ability, corrosion resistance, strong coating adhesive force and can keep the novel luster for a long time. It can realize highly effective construction business requirements and it has become the ideal composite material in household appliance, light industry, machinery, electronics and other industries.