Abstract: Anthracite, as a rare and valuable coal resource, holds substantial economic potential through deep desliming and quality enhancement. This study reveals that the introduction of sodium lignosulfonate during the ultrafine grinding process of anthracite facilitates the coupled regulation of interfacial properties within the ultrafine grinding-flotation system. Experimental results demonstrate that the addition of sodium lignosulfonate enhances grinding efficiency. Furthermore, flotation tests indicate that sodium lignosulfonate, when employed as a grinding aid, exerts a pronounced influence on flotation performance. An optimal dosage of 500 g/t sodium lignosulfonate significantly improves flotation deashing efficiency; however, excessive addition negatively affects the flotation process. Characterization analyses combined with EDLVO theoretical calculations further elucidate that sodium lignosulfonate enhances the hydrophilicity of coal particle surfaces, effectively suppresses spontaneous particle aggregation, and mitigates “mechanical entrainment” during flotation. This study proposes a novel technical approach, offering both theoretical insights and practical guidance for the industrial application of coupled interfacial regulation in the ultrafine grinding-flotation process of anthracite.