A detailed process mineralogy study of a gold concentrate was carried out.Based on that,a biological oxidation-cyanidation leaching test was carried out for verification,investigating the gold loss state.The results show that the gold concentrates have a gold grade of 38.71 g/t and contain sulfur 19.69 % and arsenic 22.01 %,belonging to high-arsenic and high-sulfur gold concentrates.The gold minerals,in terms of embedding status,are dominated by encased gold with very fine grains,the dominant microgranular gold accounting for 99.53 %.The biological oxidation-cyanidation leaching process obtains a gold leaching rate of 84.04 %;the gold lost in leaching residue is mostly lost in arsenate mixtures,except for gangue minerals wrapping,and a little is lost in metallic sulfide;target minerals have good leaching performance and the gold loss characteristics are consistent with process mineralogy study results.