Preparation method of imidazoline corrosion inhibitor

The invention provides a preparation method of an imidazoline corrosion inhibitor, the raw materials of which include: an organic acid, which consists of caprylic acid, capric acid, hexanoic acid, lauric acid, oleic acid, linoleic acid, palmitic acid, stearic acid, tetradecanoic acid, and naphthenic acid that has a molecular weight of 180-350; and an amine material, which consists of hydroxyethyl ethylenediamine, diethylenetriamine, triethylene tetramine, and tetraethylenepentamine. The preparation method comprises: taking the organic acid and amine raw materials to conduct preparation in a mole ratio of 1:1.1-1.3, placing them in a three-neck bottle to conduct heating in order, when the acid is completely melted, starting stirring, leaving the materials to react for 2-3h under the condition of 115-125DEG C, then raising the temperature to 180-200DEG C within 2h, carrying out heat preservation for 2.5-3.0h, further raising the temperature to 270DEG C within 2h, and leaving the materials to react for 2-3h at 265-275DEG C, thus obtaining the imidazoline corrosion inhibitor.