The invention provides an environment-friendly corrosion-prevention metal oil-rust removing agent and a preparation process thereof. The oil-rust removing agent is prepared from the following components in parts by weight: acetic anhydride, itaconic acid, 1,3-butylene glycol, oleic acid, nano-zirconia, 8-hydroxyquinoline, boric acid, caprolactam, nano-cerium oxide powder, disodium ethylene diamine tetraacetate, saponin powder, heterogeneous alcohol polyoxyethylene ether, matrine, methylisothiazolinone, thiourea, 3-amino-4-octanol, sodium citrate, deionized water and ethanol. The oil-rust removing agent provided by the invention has an integral oil-rust removing effect, the rust removing time is only 5-10 minutes, the surface of metal is bright and has no obvious rust trace after the rust removing treatment, obvious rust spot or rust trace is not generated after the metal which is subjected to oil-rust removal is placed at the room temperature for 1 month, and the metal is good in corrosion resistance, does not secondarily rust within 2 months and does not generate smoke, so that the oil-rust removing agent is safe to use, environmentally friendly and suitable for being popularized and used.