This paper presented a novel flue gas desulfurization (FGD) process. In this method, organic amine was used to absorb sulfur dioxide in flue gas. The vapor-liquid equilibrium model of absorption of sulfur dioxide in the flue gas by an organic amine was established, and the vapor-liquid equilibrium of the sulfur dioxide-ethylenediamine-phosphoric acid-water system was first predicted. For a 0.3 mol(.)L(-1) ethylenediamine buffer solution system, the predicted results fit the experimental results well. It is indicated that the model is preferable to predict vapor-liquid equilibrium under the experimental conditions. Using an ethylenediamine-phosphoric acid aqueous solution as the absorbent, some technology conditions such as the temperature, gas-liquid ratio, pH value, concentration of the desulfurization reagent, and liquid flow rate in absorption and deabsorption were experimentally researched on the circle divide 30 mm x 600 mm packed tower in the laboratory. The optimized conditions were finally specified after experiments. The novel FGD method presented in this paper has advantages such as high desulfurization efficiency and low investment and unit FGD expense. It is suggested that this novel method be applied to the FGD process in power plants using high sulfur coal as the fuel.