In response to issues such as slow oxidation rate and low efficiency caused by insufficient mineral liberationin the bio⁃oxidation process of gold concentrate, the synergistic effect between selective grinding and the bio⁃oxidation⁃carbon⁃in⁃leach for gold extraction process was studied. Through experimental and industrial case studies, its impactson oxidation efficiency, gold recovery, and pollutant control were analyzed. Industrial application results demonstratethat after implementing selective grinding technology. The S2− oxidation rate increases by 0.71 %, and the carbon⁃in⁃leachgold recovery improves by 3.81 %. The concentrations of thiocyanate and ferrocyanide in the carbon⁃in⁃leach tailingsdecrease by 34.40 % and 27.99 %, respectively. This technology can provide valuable reference for enhancing qualityand efficiency and reducing pollution in bio⁃oxidation processes within the gold industry.