Abstract: In this study, with the circulating fluidized bed desulfurization(CFB-FGD) tower as the research focus, the computational particle fluid dynamics(CPFD) method was employed to conduct simulations and analyses of the flow field within the desulfurization tower. Additionally, the impacts of the change in the flue angle and the residence time on the performance of the desulfurization tower were investigated. The results show that the flue angle increases from 28°to 35°, the vortex at the flue angle decreases, and the flow is improved. When the height of the straight pipe section of the desulfurization tower is 18000mm, the removal rate of SO2 in the section is 99.56 %, and the evaporation rate of the desuperheating water is 94%, which can achieve efficient desulfurization.