The impurity content in the molybdenum concentrate produced from the flotation process of a porphyry molybdenum ore is high.To solve the problem,experimental research on the flotation process is carried out and investigates the influencing factors such as reagent regime and grinding fineness.The results show that when the process of the bulk flotation of copper and molybdenum-flotation to separate copper and molybdenum is adopted,and the optimal reagent regime and regrinding fineness are applied,the molybdenum concentrate obtained has a grade of 57.13 %,the copper and lead indexes are greatly reduced,the copper content decreases from 0.2 %-0.5 % to 0.037 %,the lead content decreases from 0.2 %-0.83 % to 0.014 %,the molybdenum recovery rate increases from about 87 % to 91.02 %.The research provides a technical basis to optimize the ore-dressing process.