The invention discloses application of 1-myristyl-3-methylimidazolium chloride ionic liquid serving as a steel corrosion inhibitor. The method of the application comprises the step of: immersing steel in acid liquor containing the corrosion inhibitor of the 1-myristyl-3-methylimidazolium chloride ionic liquid to clean the steel. The invention has the advantages that the ionic liquid is used as the corrosion inhibitor and is extremely easy to dissolve in common solutions in production, such as water and the like, which is beneficial to the penetration in the use of the corrosion inhibitor; compared with common inorganic corrosion inhibitors, the corrosion inhibitor of the invention does not have toxic action on the environment and organisms and makes up the defect of big toxic and side effects on the traditional corrosion inhibitors. The corrosion inhibitor can effectively restrain the corrosion reaction of steel materials in acid media and has good corrosion inhibition efficiency.