A single coal tar pitch anticorrosion paint has excellent water resistance, low cost, thick film coating, and easy to invade the surface of steel that is not fully rust-removed. After long-term exposure, the volatile matter contained in the paint will escape and crack. The thermosetting resin modified coal tar coating has excellent adhesion, can be formulated into a wide range of hardness and flexibility of the coating, the dry film thickness up to 0.2 ~ 1.3mm, while having very good abrasion resistance and impact resistance . Polymer-modified coal tar coatings require special topcoats designed to prevent delamination and overcome some other film defects. Add a pigment, such as iron red, to a deep red color. However, other color improvement methods have not been successful. In such coatings, ** pigments are often added. It is difficult for a coal tar coating to use a coating process to avoid pinholes and defects. Therefore, it is generally necessary to use multiple treatments. Coal-tar paint without resin modification cannot be used outdoors because the sun will harden, crack, shrink the surface layer.