The coupling of MoS2 with In2O3 is a well-known challenge due to the lower stability of MoS2 in the presence of oxygen at high temperature. In the present work, stable mesoporous MoS2@In2O3 composites were designed by a sonochemical reaction and a low temperature hydrothermal method, in which MoS2 nanosheets (NSs) were vertically planted on highly mesoporous In2O3 nanocubes. The mesoporous MoS2@In2O3-II nanocomposite with a MoS2 and In2O3 mass ratio of 1:1 exhibited a high response of 10.3-100 ppm NOx, and ultrafast response time of 1-9 s from 100 to 0.1 ppm. The enhance gas response of MoS2@In2O3-II reveals the synergistic effect of the interfacial transfer of electrons from In2O3 nanocubes to MoS2 NSs, and the highly exposed active edges of vertically aligned MoS2 NSs. The MoS2@In2O3-II sensor is a promising candidate as a gas sensing material due to its excellent structure and outstanding properties at room temperature (RT).