Wet flue gas desulfurization is now a widely used method for SO2 abatement, but an efficient adsorbent with low cost is recognized as being an important prerequisite for its industrial application. Herein, wet flue gas phosphate rock desulfurization technology is reported to eliminate SO2 from phosphorus chemical processes, and the technology has been employed in industrial application successfully. Because phosphate rock was chosen as the raw material from the phosphorus chemical process, its application can reduce the desulfurization cost. In addition, the produced sulfuric acid in the present desulfurization system can provide replacement of sulfuric acid required in typical phosphorus chemical activity. Accordingly, this desulfurization technology is of environmental and economic importance and also exhibits potential in treating other industrial SO2 pollution processes. Characterizations of the fresh and spent phosphate rock samples as well as analysis of the spent solution were conducted. Subsequently, the reaction processes, the desulfurization mechanism, and the deactivation of the phosphate rock adsorbent were proposed.