The invention discloses a water-based epoxy anti-corrosive coating and a preparation method thereof, and relates to a ship antirust and cabin inside and outside antirust fireproof paint. The invention provides a water-based epoxy coating with the VOC lower than 10g/l, and the coating belongs to an environment-friendly coating, which not only has the antirust performance of anti-corrosive coating,but also has low flame propagation of cabin inside finish paint, meets the requirement of cabin inside smoke and toxin, resists aging, and is a multifunctional water-based coating, and the bottom andthe surface are combined. Zhejiang Ampang AB-EP-20 is used as the epoxy resin, Zhejiang Ampang AD-HGF is used as the curing agent, and fluorocarbon emulsion (the model of which is Beijing Baowei PF-1) is used as the base material. Wetting dispersant, defoamer I, defoamer II, flash rust inhibitor, thickener, defoamer and substrate wetting agent are used as additives, rutile titanium white powder, compound zinc phosphate, ferrotitanium powder, talcum powder, ultra-fine aluminum hydroxide, precipitated barium sulfate, mica powder and aluminum tripolyphosphate are used as pigment fillers.