In this paper, In2O3 nanospheres and NiO nanoparticles decorated In2O3 nanospheres with enhanced methane (CH4) sensing performance were successfully synthesized via a facile solvothermal method and the subsequent calcination process. Diverse characterization technologies such as X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were employed to identify their compositions, morphologies and nanostructures. The methane sensing performances of the NiO/In2O3 nanocomposites were compared with the pure In2O3, and the results indicated that the decorating of NiO significant enhanced the sensing capability. The response value of the NiO/In2O3 nanocomposites toward 500 ppm CH4 was ∼13.057, which was nearly 10.3 times higher than that of pure In2O3 at 120 °C. In addition, the optimal operating temperature of In2O3 was reduced from 180 °C to 120 °C after decorated by NiO. Meanwhile, the NiO/In2O3 nanocomposites also displayed the excellent selectivity, good repeatability and stability. This research confirmed that the promising application for CH4 detection of the NiO/In2O3 nanocomposites.