The easy-cleaning pre-painted steel sheet is a new pre-painted steel sheet for outdoors construction. Its organic coating not only has excellent properties of decoration and weatherproof that common pre-painted steel sheets might possess but also has the special self-cleaning function. The factory buildings built by the pre-painted steel sheets of this kind need not any manually-operated cleaning or maintenance, which can retain the cleanness and glossiness of the pre-painted steel sheets applied to the walls and roofs only by rainwater, even those in the industries and cities with poorer only by rainwater, even those in the industries and cities with poorer air quality, and can maintain the high decorative property of the pre-painted steel sheets.