The invention discloses a specific inhibitor application in complex sulfide ore. The inventive organic compound contains mineral-philic group -SH, hydrophilic group -COOH, -OH, -SO3, etc. in molecular structure, which fully shows the inhibiting property against pyrrhotite, pyrite and chalcopyrite in complex sulfide ore flotation separation, and is a high selectivity desulphurizing inhibitor. Compared with the prior inorganic inhibitors such as cyanide, lime, zinc sulfate, trisodium phosphate, dichromate, potassium permanganate, sodium sulfide, sulfite, etc., the inventive inhibitor has the advantages of low usage amount, good index and no pollution.