A detailed process mineralogical study was conducted on a polysulfide gold-copper ore.Based on the study,flotation experiments were carried out,and the loss of gold and copper was investigated.The results showed that gold copper and sulfur are valuable elements,with gold grade of 0.60 g/t,copper grade of 0.17 %,and sulfur content of 16.13 %.The main copper mineral is chalcopyrite,predominantly in fine grains with high degree of monomer dissociation.The main gold mineral is native gold,predominantly in fine grains,with sulfide-encased gold accounting for 49.05 %.The joint process of regrinding-gravity tailings bulk flotation-copper-sulfur separation from the bulk concentrate(three-stage cleaning) achieved total recovery rates of 91.70 % for copper,50.21 % for gold,and 90.93 % for sulfur.The recovery effect of the target minerals was good,and the loss of gold and copper in the tailings was mainly due to inclusion in gangue minerals,consistent with the results of the process mineralogical study.