Abstract: The porphyry type ore of Yulong Copper Mine contains 0.73% copper and 0.044% molybdenum, among which copper minerals are mainly chalcopyrite and chalcopyrite, molybdenum minerals are mainly molybdenite, and gangue minerals are mainly quartz. On site, the “molybdenum and copper instant flotation-copper enhanced flotation-combined separation” is adopted. Under the condition of the original reagent system, the concentrate with copper and molybdenum grade of 22.67% and 1.360% and recovery of copper and molybdenum of 85.07% and 81.74% can be obtained by closed circuit test. In order to further improve the recovery of copper and molybdenum, the reagent system of porphyry ore is optimized without changing the process structure. The research results show that using BK404C and BK345 as collectors in molybdenum copper instant flotation can ensure the recovery of molybdenum, while also maximizing the recovery of copper; The use of BK404B and BK404C as collectors in copper enhanced flotation can enhance the recovery of copper that failed to float in molybdenum copper instant flotation operations. The concentrate with copper and molybdenum grade of 23.27% and 1.340% and the recovery of copper and molybdenum of 87.14% and 82.24% can be obtained by the closed circuit test of the optimized reagent system, which achieves the goal of improving copper molybdenum recovery.