The invention relates to the technical field of metal corrosion prevention, in particular to a rustproof corrosion inhibitor and a preparation method and application thereof. The rustproof corrosion inhibitor is mainly prepared from, by weight, 1-10 parts of phytic acid, 60-85 parts of water, 0.1-1 part of acrylamide, 0.05-0.3 part of glutamic acid, 1-5 parts of sodium benzoate, 5-15 parts of triethanolamine, 1-5 parts of ethanolamine, 0.1-1 part of disodium hydrogen phosphate, 5-15 parts of sodium molybdate, 0.2-2 parts of a complexing agent, 0.5-3 parts of a film forming agent and 0.1-1 part of a defoaming agent. According to the rustproof corrosion inhibitor and the preparation method and application thereof, the corrosion speed of metal materials can be effectively decreased, and the corrosion resistance and the rust prevention property are good; and the rustproof corrosion inhibitor is particularly suitable for corrosion prevention and rust prevention of steel metal materials washed by ultrahigh-pressure water jet flow, and the problem that after ultrahigh-pressure water jet flow cleaning is conducted during maintenance, naval ships are prone to corrosion before coating can be effectively solved.