The effects of silver sulfide (Ag₂S) on the bioleaching of chalcopyrite and pyrite were investigated in this paper. It has been shown that Ag₂S enhanced the yields of bioleaching of chalcopyrite but inhibited the bio-oxidation of pyrite. The addition of Ag₂S selectively increased the copper dissolution from the chalcopyrite-containing ores in shake flasks with a recovery of 85.3% compared with 24.3% without Ag₂S, while slightly decreased the iron yields from 51% to 41.8%. The copper extraction of the chalcoopyrite-containing waste rock in column leaching charged with 18 kg mass increased up to 21.7% in the presence of Ag₂S, while only 3.4% in the absence of the catalyst. The mechanism of Ag₂S catalysis could be explained well by the “Mixed potential model”.