The invention provides an axial chiral imidazole salt compound and a preparation method thereof. The structural formula of the axial chiral imidazole salt compound is that a binaphthol derivative and halogen reacts firstly to obtain a intermediate product which is coupled with o-phenylenediamine to obtain a single substituted axial chiral o-phenylenediamine compound and a axial chiral o-phenylenediamine compound with symmetrical C2. The single substituted axial chiral o-phenylenediamine compound and a heterocyclic aromatic halogenated compound or an aryl trifluoroacetic acid ester compound react to obtain an intermediate product, and the intermediate product and ortho-acid trialkyl ester react to obtain the axial chiral imidazole salt compound with R3 which is aryl. The single substituted axial chiral o-phenylenediamine compound and the ortho-acid trialkyl ester react to obtain a intermediate product, the intermediate product and a halogenated alkyl compound react to obtain the axial chiral imidazole salt compound with R3 which is alkyl. The axial chiral imidazole salt compound preparation method is high in synthesis yield, raw materials are cheap and easy to obtain, and the chiral center of the obtained axial chiral imidazole salt compound is close to a reaction point, thereby being favorable for obtaining high asymmetrical selective results.