Abstract: Wet plume forms when the wet flue gas from the wet desulphurization system exits into the ambient air, which would bring about visual pollution. The formation and dispersion process of wet plume was analyzed. The effects of wet plume elimination technologies, such as direct heating, cooling and reheating, direct cooling, on the diffusion characteristics of particulate, SO₂ and NO₂ were investigated. The results showed that the wet plume elimination technologies have little effect on ambient particulate concentration; the ratio of maximum ground-level particulate concentration to ambient particulate standard is less than 1.5%, which indicates that the maximum ground-level particulate concentration is much lower than that of Ambient Air Quality Standard(GB 3095-2012). The direct heating as well as cooling and reheating of flue gas can promote the diffusion of SO₂ and NO₂, and the ratios of maximum ground-level concentration of SO₂ and NO₂ to ambient standard values can be reduced by 31.5% and 15.1%, respectively by the two technologies. By direct cooling of flue gas, the ratios of maximum ground-level concentration of SO₂ and NO₂ to ambient standard values are less than 20% and 70%, respectively, which shows that the maximum ground-level concentrations of SO₂ and NO₂ are below the air quality standards.