An efficient electrocatalyst for oxygen evolution has been prepared via the deposition of iron-nickel layered double-hydroxide (FeNi-LDH) nanosheets on 3D carbon network as the building scaffold in a one-step hydrothermal process. It is found that upon the assembling of FeNi-LDH nanosheets with graphene into the 3D cross-linked hybrid, the FeNi-LDH/graphene hybrid features a well-improved catalytic activity towards the oxygen evolution reaction (OER) with a good stability during the long-term cycling experiment. Moreover, the hybrid catalyst is also active in the oxygen reduction reaction (ORR), qualifying it as a new type of bifunctional catalyst that can work in metal-air batteries.