The invention relates to a water-based modified pure acrylic acid anticorrosive paint which is prepared from the following components in percentage by mass: 30-45% of modified acrylic acid emulsion, 3-5% of film-forming assistant, 0.6-1.2% of dispersant, 0.1-1.0% of defoaming agent, 0.1-0.2% of wetting agent, 0.05-0.10% of mold preventive, 1-2% of flash-rust inhibitor, 2-5% of pigment, 15-30% of antirust pigment and filler, 2-5% of filler, 2-5% of thickening agent, 1-2.5% of salt-fog inhibitor and the balance of water. The pH value is regulated to 8-9. The anticorrosive paint provided by the invention has the advantages of combined primer and precoat functions, single component and self drying, is water-based, and satisfies the requirement for environmental protection. The invention has the advantages of simple production technique, accessible raw materials, low cost, low VOC (volatile organic compound), environmental protection and high safety, can easily implement industrialization, and is simple and convenient for construction.