The swirling blade nozzle structure was introduced at the inlet of flue gas in the spouted bed to enhance interphase mixing and improve the desulfurization efficiency. The computational fluid dynamics (CFD) and experimental methods were used to study the gas–solid two-phase flow, water vaporization and semi-dry flue gas desulfurization processes in a spouted bed with an integral swirling blade nozzle (SB with an ISBN). It is found that the introduction of the swirling blade can significantly intensify heat and mass transfer process in spouted beds, the gas–liquid-solid temperature in the SB with an ISBN is higher than that of the conventional SB. During the desulfurization process, the desulfurization efficiency of spouted bed with an ISBN is about 85.42 %, while that of conventional SB is 76.14 %, and the desulfurization efficiency is increased by 12.2 %.