Abstract: TiO2 is widely used in the production of gas-sensor, solar cell and potocatalytic degradation, due to its good stability, non-poisonous nature and strong sensitivity to gas and wettability. TiO2 nanotubes are typical one-dimensional nanomaterials with relatively extensive chemical and physical properties. As the production cost is low, it has a wide application prospect. In particular, recent studies suggest that compared with other forms of nano-materials, it has a larger specific surface area, stronger adsorbability and good nanometer size effects. TiO2 nanotubes have a great potential in fields of photocatalysis, sensors, solar cells and others and have attracted much research interest. Although the production of TiO2 is a mature technology, its application in the field of gas-sensors remains an issue to explore. The preparation of TiO2 nanotubes is the important prerequisite for its application in various fields, so main preparation methods of TiO2 nanotubes firstly are discussed in this paper to understand the shape and general components of TiO2 nanotubes. The application of TiO2 nanotubes in gas sensors is specifically addressed among its many applications.