Two kinds of imidazole ionic liquids(PF_6and BF₄) are synthesized from N-methyl-midazolium, chlorobutane, KPF_6and NaBF_4under microwave irradiation and water bath heating respectively by two-step method. The advantage and disadvantage in the synthesis of intermediate and anion exchange are compared, and the structure characteristics and electrochemical performance are characterized. The result shows that the ionic liquids synthesized by two different methods have no evident discrepancy. The reaction time can be cut down markedly under the microwave, and the productivity can exceed 90%, while the water bath heating is propitious to anion exchange. So combining the two methods will get a favorable result.