The invention discloses a method for preparing imidazole acetate ionic liquid, which comprises the following steps of: mixing organic alcoholic solution of imidazole halid salt and organic alcoholic solution of acetate, and reacting at preset temperature; evaporating to remove partial organic alcohol in a reaction system in the reaction process; and filtering reaction mixed liquor and removing organic alcohol from filtrate to obtain the imidazole acetate ionic liquid. In the method for preparing the imidazole acetate ionic liquid, the partial organic alcohol is evaporated and removed in the reaction process, so distillation can be performed by means of reaction temperature, the load of evaporating and removing a solvent after filtration is reduced, the cost is reduced, the solvent amount in the filtrate is small, and the inorganic salt amount remained in the solvent is small; therefore, the purity of the imidazole acetate ionic liquid subjected to solvent evaporation and removal is improved.