The invention discloses a normal-temperature corrosion-resistant phosphating solution and a preparation method thereof. The normal-temperature corrosion-resistant phosphating solution is prepared from the following raw materials in parts by weight: 35-56 parts of deionized water, 6-8 parts of sodium molybdate dehydrate, 2-7 parts of chromic acid, 5-8 parts of hydroxylamine sulphate, 4-8 parts of methyl methacrylate, 4-5 parts of sodium fluoroborate, 4-9 parts of tartaric acid, 22-24 parts of citric acid, 2-6 parts of cyclohexanehexol hexaphosphate ester, 1-8 parts of ammonium cuprate, 2-6 parts of m-nitrobenzene, 3-6 parts of sodium silicate and 6-10 parts of manganese dihydrogen phosphate. Compared with a conventional phosphating solution and a conventional phosphating process, the normal-temperature corrosion-resistant phosphating solution disclosed by the invention has the advantages that when a workpiece is subjected to phosphating by adopting the normal-temperature corrosion-resistant phosphating solution, the phosphating process is simplified, the phosphating efficiency is improved, and the phosphating cost is reduced; meanwhile, a phosphating film formed by adopting the normal-temperature corrosion-resistant phosphating solution not only is denser and more uniform, but also can be used for effectively protecting the workpiece from corrosion; and the preparation method is simple and low in cost.