In a molybdenum-copper-bismuth polymetallic sulfide ore, the bismuth content was 0.52%, primarily occurring as bismuthinite and native bismuth. The molybdenum and copper contents were relatively low at 0.094% and 0.048%, respectively, mainly existing in the form of molybdenite and chalcopyrite. Notably, the four minerals (molybdenite, native bismuth, chalcopyrite, and bismuthinite) exhibit a remarkably close intergrowth relationship. A processing flowsheet of "bulk flotation of Mo-Cu-Bi followed by regrinding and sequential separation" was developed to achieve efficient resource recovery and comprehensive utilization. Experimental results demonstrated that using "diethyldithiocarbamate (DDTC) + diesel oil" as combined collectors enabled effective co-recovery of molybdenum, copper, and bismuth. After regrinding and reagent removal treatment, satisfactory separation efficiency was achieved, producing high-grade concentrates for each metal. Laboratory-scale closed-circuit tests yielded the following indicators: molybdenum concentrate grading 51.64% Mo with 88.24% recovery; copper concentrate containing 15.84% Cu with 55.95% recovery; and bismuth concentrate assaying 52.69% Bi with 82.23% recovery. This innovative process successfully realizes comprehensive utilization of mineral resources, demonstrating significant economic benefits and environmental advantages.