A complex lead-zinc sulfide ore from Inner Mongolia Autonomous Region, China, was subjected to this work. Research on mineral processing was conducted according to the properties of the lead-zinc ore. The lead minerals are successfully separated from the zinc minerals with the combination of collectors. Compared to CuSO4, new reagent X-43 as zinc activator shows its advantage in marmatite flotation. With the process utilized in this work, a lead concentrate of 59.67% Pb with a recovery of 78.69% and a zinc concentrate of 50.99% Zn with a recovery of 81.98% are produced. The silver recovery in the lead concentrate is 56.76% while the indium recovery in the zinc concentrate is 42.60%.