Abstract: During the gasification process, sulfur and mercury in coal can migrateinto gas, wastewater, and gasification slag causing environmental pollution. Sulfur and mercury have strong affinities, and understanding the migration behavior of these elements during gasification is of great significance for proposing scientific control methods. In this study, the adsorption properties of Hg⁰ on gasification slag under different working conditions are investigated by a fixed bed performance evaluation device, and the reaction characteristics of sulfur and mercury on the surface of gasification slag are revealed by N₂ adsorption-desorption, SEM, XPS, and other characterization methods. The results show that sulfur and mercury are mainly concentrated on the surface of fine slag, which has good Hg⁰ adsorption performance, and physical adsorption plays a leading role. It is found that the higher the content of unburned carbon and minerals, the better the reactivity of sulfur and mercury on the surface of gasification slag. In addition, the atmosphere also affects the Hg⁰ adsorption performance of the gasification slag. These findings provide a new idea for the high-value resource utilization of coal gasification slag, and also provide theoretical guidance and research basis for the collaborative removal of sulfur and mercury in syngas, thus contributing to the sustainable development of clean coal technology.