This article summarizes different methods for removing sulfur dioxide (SO2) from industrial flue gas to reduce air pollution. It compares the pros and cons of dry, semi-dry, and wet desulfurization technologies. The research reviews how these methods work and points out current challenges and future research directions. By studying how to recycle desulfurization byproducts, we can create more valuable desulfurization processes. The goal is to help improve desulfurization technologies for cleaner air.