The invention discloses a method for preparing geranyl acetate under the catalysis of acidic functionalized ionic liquid. The method comprises the following steps: subjecting acetic acid and geraniol to esterification under the catalysis of the acidic functionalized ionic liquid; and after complete reaction, subjecting a reaction solution to after-treatment so as to obtain geranyl acetate. The structure of the acidic functionalized ionic liquid is as shown in a formula (II), i.e., [X(CH<2>)SO<3>H]<+>Y<->. In the formula (II), X is R<1>(R<2>)(R<3>)N-, and R<1>, R<2> and R<3> are independently selected from C1-C5 alkyl groups; n is an integer in a range of 1 to 5; and Y<-> is a hydrosulfate radical, a sulfonate radical, a methanesulfonate radical, a trifluoromethanesulfonate radical, a benzenesulfonate radical or a p-toluenesulfonate radical. The method provided by the invention is high in conversion rate, few in side reactions, high in product yield and purity and simple in after-treatment, and has important industrial application value.