Abstract: The agents currently available for removing mercury in coal-fired powers are expensive and are inefficient in removing and effectively recycling mercury. By investigating the process of multimetal functionalization modification, an integrated process route for preparing, removing, and separating biochar composite mercury removal agents based on the coprecipitation method is proposed to solve this problem. By combining multiple characterization means, the coupling correspondence between the physical and chemical structure of biochar and its removal performance and antistatic separation properties is revealed. Using the temperature programmed desorption technique and adsorption kinetic model, the key action mechanism of multimetal functionalized modification on the microscopic properties of biochar is clarified, and the deep-level differential mechanism between the dual inverse modification processes of Hg⁰ removal and antistatic separation are revealed. It is found that samples modified by multimetal functionalization show a significant improvement in Hg⁰ removal, up to 5 times that of the unmodified sample. The samples have excellent antistatic separation properties by changing the electrical conductivity of the loaded modified substances. By optimizing the coordination state of alkali metals, the interlayer structure of graphite microcrystals, the richness of pore structure, the fugacity of oxygen-containing functional groups and doped metals, the synergistic enhancement in mercury removal and antistatic separation performance can be facilitated.