The invention provides a waterborne one coat anticorrosive paint. The paint comprises the following components by weight percent: 20%-60% of waterborne polyurethane modified epoxy resin, 5%-25% of deionized water, 0.5%-5% of dispersant, 0.1%-5% of defoaming agent, 0.1%-5% of substrate wetting agent, 10%-40% of pigment and filler, 0.5%-10% of pH regulator, 0.5%-10% of thixotropic agent, 0.5%-5% offilm-forming additive, 1%-5% of light stabilizer, 0.5%-5% of flash rust inhibitor and 0%-10% of salt-fog resistance additive. The invention provides the waterborne one coat anticorrosive paint which uses waterborne polyurethane modified epoxy resin as base material and is prepared by adding various additives into the base material. The anticorrosive paint has higher corrosion resistance and agingresistance; tests show that the ultraviolet aging resistance is up to 600h; the thermal stability is good, the paint can be cured at the room temperature after being sprayed; and the construction technology which integrates the primer coating and the finish coating into one step is simple.