The invention relates to a preparation method for an anticorrosion iron-
coating film, belonging to the technical field of 
metal coating films. According to the invention, a 
corrosion inhibitor is prepared by reacting 
ascorbic acid with 
phytic acid; since the 
ascorbic acid has the characteristics of 
low toxicity or non-
toxicity and low price, and 
oxygen atoms in molecules thereof have strong 
electron donating ability, a firm adsorption protective film can be formed on a 
metal surface, and can stably exist under alkaline conditions; after bonding of the 
ascorbic acid with the 
phytic acid, when 
phosphate molecules contacts with the surface of a material, hydrophobic chains in the molecules are adsorbed on the surface of the material so as to form a continuous adsorption layer, and hydrophilicgroups thereof face air; since the molecules contain -OH, the molecules can form 
hydrogen bonds with water molecules, and an adsorbed 
water layer forms a conductive film, so the surface conductivityof the material is enhanced, static charge accumulation on the surface of the material is reduced, and an infiltration path which 
oxygen molecules takes to reach the surface of a substrate is extended; and the anticorrosion iron-
coating film has excellent barrier properties, improved 
corrosion resistance, and good application prospects.