To improve the activity of oxygen reduction reaction (ORR) of microbial fuel cell (MFC), the cathode was modified by using NiFe layered double hydroxide (LDH)@Co3O4 as catalyst to increase the power generation of MFC. The unique NiFe-LDH@Co3O4 core-shell structure was prepared by using NiFe-LDH as metal source, Co3O4 as support matrix and urea-doped nitrogen in LDH. XRD, FTIR, SEM and EDS showed that LDH was successfully grown on the surface of Co3O4, and had typical LDH nanostructure. The voltage output of NiFe-LDH@Co3O4-MFC was maintained at about 0.43 V, with insignificant variations over 8 d, which indicated that NiFe-LDH@Co3O4 catalyst has remarkable stability and durability. Moreover, the maximum power density was 467.35 ± 8.27 mW/m2, which was produced by NiFe-LDH@Co3O4. The results implied that the improvement of ORR activity of NiFe-LDH@Co3O4 was due to its high conductivity and abundant active sites, and therefore, the power generation capacity of MFC was improved. The electrode prepared by NiFe-LDH@Co3O4 modified air cathode was a promising material for fuel cell.