Nanorod-like CoFe2O4 was synthesized via hydrothermal technique and subsequent annealing process. The CoFe2O4 was doped in activated carbon (AC) as air cathode catalyst in microbial fuel cell (MFC). The obtained maximum power density (MPD) of MFC with 10% CoFe2O4 reached as high as 1780 +/- 20 mW m(-2), which was 1.99 times higher than that with bare AC. The electrochemical studies showed that CoFe2O4-doped AC exhibited superior kinetic activity of electron transfer and low resistance through four-electron reaction pathway. CoFe2O4 introduced binary metal as active sites during the oxidative recombination of the metal mixture. Besides, the first principle calculations proved that CoFe2O4 had better ORR activity comparing with Co3O4 and Fe3O4. It is verified experimentally and theoretically that CoFe2O4 will be an excellent cathodic catalyst in MFC.