Abstract: The characteristics of flue gas desulfurization using modified double-recycling and multi-stage water film tower was evaluated in this paper． In order to increase the SO2 removal efficiency，contact probability of liquid phase and flue gas was enlarged through using multi-point pH control and multi-stage water film． Factors such as flue gas velocity，pH of upper and lower tower section，ratio of liquid-flue gas and inlet SO2 concentration were selected to research the desulfurization effect． The result showed that SO2 removal efficiency kept above 93% when the inlet SO2 concentration was less than 5 000 mg /m3 ． There was no aggradation of CaSO4 or CaSO3 under the optimized pH condition of 6. 0 and 5. 0 for the upper and lower section of the tower，and 15 of L/G． The system has a favorable future of application，and a considerable reference for debugging and running of spot desulfurization equipments．