In the production of a  gold copper mine,the ore-dressing indexes of gold and copper decline because of changing ore property.In light of that,based on lab tests,the study investigated systematically the flowsheets of on-site grinding grading operation and flotation operation,diagnosed the problems on site and carried out process optimization.By adopting optimization measures such as controlling grinding concentration,optimizing collector types and proportion and adjusting reagent proportion,the ore-dressing indexes are greatly improved:copper recovery rate is increased from 93.36 % to 94.81 %,gold recovery rate is increased from 79.14 % to 79.55 %,creating 2.95 million yuan/a more profits.