The invention provides special antifouling powder paint for a surface layer self peeling type building aluminum plate. The paint is prepared from the following ingredients in percentage by weight: 30to 60 percent of modified substrate resin, 30 to 60 percent of functional filling materials, 1 to 3 percent of adhesion force promoters, 1 to 3 percent of charger regulating agents, 0.5 to 1.5 percentof leveling agents, 0.3 to 0.8 percent of benzoin and 0.8 to 3 percent of pigments. The powder paint is prepared by the following scheme with the steps of (1) preparing alkali-soluble resin; (2) preparing modified substrate resin; (3) after the materials are weighed according to the formula, performing uniform crushing by a high-speed stirring machine; performing fusion extrusion; (4) performingair cooling, crushing and sieving on extruded sheet materials to obtain powder paint. The cement slurry corrodes a coating at a certain thickness in a controllable way; in the cement hardening demolding process, the corroded part falls together with the cement; a new coating is exposed; the problem of no antifouling function of the special antifouling powder paint for a building aluminum plate issolved, so that the use cycle times of the coating is greatly improved; the advantages of low construction difficulty, process simplicity and the like are realized.