The invention relates to the technical field of make-up, and discloses water-based foundation make-up. The water-based foundation make-up is prepared from, by mass, 10.0-20.0% of ionized water, 4.0-7.5% of glycerinum, 1.0-2.0% of methyl glucoside stearate, 1.0-2.0% of polyoxyethylene(20)methyl glucoside stearate, 3.0-4.0% of 2-octyldodecanol, 3.0-5.0% of polyethylene glycol, 15.0-40.0% of mica powder, 0.2-1.0% of polyvinylpyrrolidone, 5.0-10.0% of talcum powder, 1.5-15.0% of iron peroxide and 0.2-1.0% of phenoxyethanol. The invention further discloses a preparing method of the water-based foundation make-up. After the water-based foundation make-up is evenly smeared on the face, as the time changes, a refreshing and beautiful makeup layer is formed on the face after water volatilizes. The water-based foundation make-up organically combines grease, foundation powder, humectant and the like by means of hydrophilic and oleophylic structures of an emulsifying agent, the foundation powder becomes hydrophilic, and therefore the water-based foundation make-up is obtained; on the water-based condition, the foundation powder in the foundation make-up facilitates makeup and is easy to smear and good in skin feeling, after the water volatilizes, the moisture preserving and waterproof effect are still powerful, and secondly the water-based foundation make-up is easy to remove.