CMK-3, a member of the ordered mesoporous carbon materials, has been considered as one of the most leading electrode materials due to its high conductivity, uniform diameter, an interconnected mesoporous structure with a large pore volume and a highly ordered hexagonal morphology. However, the relatively low specific capacity of CMK-3 can be substantially improved by hybridizing with NiO. Herein, we demonstrate a simple precipitation method followed by a calcination treatment to fabricate ultrathin NiO nanosheets (NiO-NSs) on highly ordered CMK-3 such that the final electrode composite displays a novel nanosheets-mesoporous structure. The as-synthesized electrode composite exhibits excellent electrochemical stability and high rate performance, which can be ascribed to the hybrid structures of NiO-NSs and the conductive mesoporous matrix. The porous ultrathin NiO-NSs and the inner channels of CMK-3 are beneficial for the lithium ion diffusion while the conductive interconnected CMK-3 network is favorable to fast electron transfer. The suggested nanosheet-mesoporous structure provides a promising innovative design for battery electrodes with improved electrochemical performance.