Abstract: Mercury emitted from coal-fired power plants seriously harms human health and the ecological environment. In this paper, the effect of pollutant control devices on the removal of mercury from the flue gas in the ultra-low emission coal-fired power plants were first summarized; in particular, the impact of denitration, dedusting, and desulfuration devices after the ultra-low emission retrofits on the mercury removal was highlighted. Subsequently, the research progress on the non-carbon-based adsorbents used in the flue gas cleaning, including fly ash, natural minerals, noble metals, metal oxides, and metal sulfides, was then reviewed; the factors that may influence their performance in mercury adsorption were evaluated. Lastly, based on the current research progress, it is proposed that special attention should be paid in the future to the stability and leaching toxicity of adsorbed mercury as well as the regeneration and recycling of the spent adsorbents.