The invention discloses a diverting acid acidification corrosion inhibitor and a preparation method thereof, belonging to the technical field of oilfield chemicals. According to the mass percentage of the present invention, the components of the corrosion inhibitor are quaternary ammonium salt, octylphenol polyoxyethylene ether, propynyl alcohol, butynediol, methylpentynyl alcohol, cinnamaldehyde, methanol and water. The present invention is compound alkylpyridine, quinoline, benzyl chloride, ethylene glycol, water, react and synthesize quaternary ammonium salt, and carry out with octylphenol polyoxyethylene ether, methanol, propynyl alcohol, cinnamaldehyde, water, etc. Compounding, the present invention aims to overcome the disadvantages of poor compatibility and poor corrosion inhibition effect in the existing corrosion inhibitor technology in the use of oil field diverting acid. The process route is simple, the synthetic product has no three wastes pollution, the cost is low, the raw materials are easy to purchase, and the advantages are convenient to use and the like.