The invention relates to a water-based rust-proof derusting liquid, which is prepared from following raw materials in parts by weight: 1-2 parts of octyl phenol polyoxyethylene ether, 2-3 parts of oleic acid polyoxyethylene ester, 20-23 parts of ethyl alcohol, 1-2 parts of citric acid, 2-3 parts of zinc phosphate, 1.3-2.4 parts of sodium lauryl sulfate, 1.2-2.3 parts of 2,6-di-tert-butyl-alpha-dimethylamino phenol, 1-2 parts of isopropanol, 10-12 parts of ethoxylated trimethylolpropane triacrylate, 1-2 parts of EDTA disodium, 4-5 parts of additive, and 300 parts of water. The rust-proof derusting liquid has multiple functions like rust removal, decontamination, phosphorization, passivation, surface conditioning and the like, can form a thin film on the surface of a metal due to the combined action of an organic high-molecular polymer monomer and a chelating agent, so as to play roles in isolating air and preventing oxidization; the preparation method for the rust-proof derusting liquid is simple; the rust-proof derusting liquid is easy to clear, has low cost, reacts at room temperature, can remove the rust in short time, has long rust protection time, does not corrode the metal, contains no toxic or harmful substances, and does not pollute the environment.