In order to study the addition of functional groups in ionic liquid anion and cation to achieve better absorbing of SO₂, the 1,1,3,3-tetramethylguanidine triazole (［TMG］［Triz］) is synthesized using 1,1,3,3-tetramethylguanidine and triazole as raw materials. The desulfurization performance of the synthesized ［TMG］［Triz］ is systematically studied. The desulfurization performance and desulfurization mechanism of the ［TMG］［Triz］ are discussed. The results show that the ［TMG］［Triz］ has good performance of desulfurization and regeneration. At the atmospheric pressure, 1 mol of the ［TMG］［Triz］ absorbs 2.964 mol of SO₂ at 20 ℃. With the increase of temperature, the desulfurization capacity of the ［TMG］［Triz］ decreases gradually. The molar absorption ratio increases with the increase of SO₂ partial pressure, and under the conditions of 130 ℃, the desorption rate of the ionic liquid after saturated adsorption reaches over 95%. The mechanism investigation results show that the interaction of SO₂ and ［TMG］［Triz］ is the combination of chemical absorption and physical absorption. The results have a certain reference value to improve the efficiency of flue gas treatment.