Inspired by the truth that the hierarchy structure nanocomposites can exhibit superior electrochemical performance because such structure can provide more electron transfer routes, here we reported the preparation of Fe3O4@N-rGO nanocomposites which can match this point. The power conversion efficiency (PCE) of the cell with Fe3O4 nanoparticle as counter electrode is 6.85% while PCE for the cell with Fe3O4@N-rGO nanocomposites as counter electrode shows great enhancement, and the highest value is up to 8.18%, even higher than Pt's efficiency (7.17%) in the same environment. The great performance can be ascribed to the hierarchy structure of N-rGO and the excellent conductivity of Fe3O4 to achieve dual-functional structure optimization. The 2D hierarchy structure N-rGO film in the hybrids plays two important roles: the more active sites for dispersed Fe3O4 nanoparticles promoting catalytic efficiency and the higher electrical conducting structure for quickly charge transfer. The 2D hierarchy structure N-rGO film will be a great help for Fe3O4 particles as CE application in DSSCs.