In this work, NiMoO hollow nanocubes were first successfully obtained via facile solvothermal and subsequent etching process. Assembling two-dimensional NiMoO nanosheets into the three-dimensional framework based on CuO nanocubes provided outstanding nanostructure stability and excellent electrochemical property. For example, the as-prepared hollow NiMoO nanocubes exhibited an outstanding capacitance of 1093 F g at 1 A g. In addition, the supercapacitor is composed of hollow NiMoO nanocubes as positive electrode and N-rGO as negative electrode, which showed an outstanding energy density (44.01 Wh kg) at a power density of 769 W kg in a voltage windows of 0–1.55 V, and even maintained an energy density (23.68 Wh kg) at a high power density (7.7 kW kg). Furthermore, the device delivered a promising long-term cyclic performance of 84.7% capacitance retention after 5000 charge–discharge cycles.