Abstract: The formulation of industrial pollution control policies and emission standards requires comprehensive understanding of SO₃ emission quantities and reduction potential in coal-fired power generation. This study establishes a calculation model and methodology for SO₃ emissions based on the complete process management of coal-fired power plants, considering both generation and removal mechanisms. Through literature review and field measurements of current SO₃ emission characteristics, various standard limit scenarios are analyzed to evaluate future emission reduction potential. Results indicate China's coal-fired power plants produce approximately 636.0 thousand tons of SO₃ annually, with total emissions reaching 150.3 thousand tons, demonstrating a 76.37% overall removal efficiency through existing technologies. Implementing a 10 mg/m³ emission limit would enable 12.64% reduction through environmental upgrades in 20% of generating units, while a stricter 5 mg/m³ limit could achieve 34.84% reduction by upgrading 40% of units. These findings provide scientific basis for establishing appropriate SO₃ emission limits and environmental regulation in the coal-fired power sector.