The Ministry of Environmental Protection of China is strict on SO₂ emission control of petrochemical enterprises according to the “13th Five-Year Plan” for national environmental protection. In order to further reduce SO₂ emission based on desulfurization process units and sulfur recovery unit, one of the domestic natural gas purification plants takes series of technical measures, such as technology of MDEA solution selectively absorbing H₂S, sulfur recovery technology of low temperature Claus, daily maintenance and SO₂ emission control during abnormal operation period. Results show that the technical measures, not only ensure a relatively high sulfur recovery rate, but also sharply reduce SO₂ emission. The SO₂ emission reduction technical measures can be applied to the promotion.