Abstract: Recently, thin film gas sensors have become a hot topic in the development of gas sensors, due to their high detection sensitivity, quick response, low cost in preparation, and easy miniaturization. In particular, the use of nanomaterials in the thin films gives these sensors incomparable advantages over conventional sensors. Solid state nanostructures have very large interface surface areas and many gas channels so the sensitivity can be greatly enhanced, which can reduce the operating temperature and sensor size. This article reviews current domestic and foreign research on nanostructured thin film sensors, and outlines the gas sensing properties of several common films with different nano-structural units. Finally, future directions in this field are analyzed.