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