Based on β-NiMoO₄ nanowire (NW) arrays grown on carbon cloth as the electrode materials, a 3D solid asymmetrical supercapacitor has been fabricated. The produced β-NiMoO₄ NW arrays on carbon cloth compared to the power of NiMoO₄ nanowires deposited directively on carbon cloth can increase the efficiency of nanomaterials participating in reactions. The cone-shaped NW arrays have a high specific surface area (99 m² g⁻¹), which can provide more electroactive sites for Li⁺ and enhance conductivity through providing short transport and diffusion paths for both ions and electrons. And the cylindrical supercapacitor can allow more β-NiMoO₄ NW arrays to saturate with electrolyte to enhance the properties of the supercapacitor. Furthermore, the electrode has a highest energy density of 36.86 W h kg⁻¹, a maximum power density of 1100 W kg⁻¹, and a large capacitance of 414.7 F g⁻¹ at a current density of 0.25 A g⁻¹, all of which demonstrate excellent behavior. And the capacitance of the supercapacitor reached 65.96% of the initial capacitance over 6000 cycles. All of these results indicated that the β-NiMoO₄ NW arrays grown on carbon cloth could be a promising candidate for high performance supercapacitors.