The present invention provides an environmental protection and high efficiency corrosion inhibitor for inhibiting salt water corrosion on carbon steel, a preparation method and a use method thereof, and relates to the field of chemistry. The corrosion inhibitor has characteristics of high efficiency, low cost, low toxicity and environmental protection, and is prepared through carrying out mixing stirring dissolving on 5-50% of a benzotriazole substance, 1-10% of benzoic acid and a salt thereof, 1-10% of molybdate, tungstate, phosphomolybdic acid and a salt thereof, and phosphotungstic acid and a salt thereof, 2-20% of an alcohol amine substance, 1-10% of an acid phosphate, 1-10% of a gluconate, 1-10% of an alkaline regulator, 1-10% of an oxygen scavenging agent and the balance of water. According to the present invention, the potassium dichromate or the sodium nitrite with high toxicity, and the non-environmental protection high phosphorus and high zinc can be replaced, and corrosion of calcium chloride salt water on carbon steel and copper can be significantly inhibited when the concentration of the corrosion inhibitor is 0.3-0.5%.