A copper molybdenum polymetallic ore with high sulfur content has copper grade 0.68 % and molybdenum grade 0.021 % and is associated with gold and silver,with sulfur content up to 8.45 %.According to the ore property,experimental study on mixed flotation agent regime was carried out.The results show that the C39 collector has good adaptability to the selection of the ores.When the amount of lime is greatly reduced,the recovery rate of molybdenum,gold and silver can be improved while the copper grade of mixed concentrate is guaranteed.The mixed concentrate obtained in the closed circuit has copper grade 23.180 %,molybdenum grade 0.637 %,gold grade 5.250 % and silver grade 341.080 %,and the copper recovery rate is 90.75 %,molybdenum recovery rate 80.99 %,gold recovery rate 76.60 %,silver recovery rate 80.17 %.The beneficiation index is good.