The invention relates to the technical field of paint compositions, particularly relates to the technical field of waterborne antirust paint, and particularly discloses special anticorrosion water paint for a steel structure. The special anticorrosion water paint comprises a base material, an assistant and a pigment filler, wherein the base material is prepared by blending 30-40% of a waterborne epoxy modified acrylic emulsion and 10-15% of a waterborne one-component self-crosslinking fluorinated siloxane-acrylate emulsion in percentage by weight; the assistant comprises a neutralizer, deionized water, a wetting dispersant, a defoaming agent, a coalescing agent, an antiflash rusting agent, a thickener and an anti-settling agent. The invention further discloses a preparation method of the anticorrosion water paint, and the anticorrosion water paint is prepared by adding and blending the components step by step. The anticorrosion water paint does not use an organic solvent, does not contain toxic heavy metals, is non-toxic, has no pungent odor, is harmless to a human body, does not pollute the environment, and is also excellent in anticorrosive property, water fastness and water tolerance.