The invention provides a titanate nanotube, and a preparation method and application thereof. The specific surface area of the titanate nanotube reaches more than 400 m<2>/g, the length is more than 1 mu m, and the diameter ranges from 5 nm to 15 nm. The titanate nanotube is of an asymmetric structure with three layers on one side and four layers on the other side, and the distance between two adjacent layers is about 0.7 nm. According to the invention, the titanate nanotube is prepared at a relatively-low temperature by a simple method under the condition of not adding any surfactants and templates. The preparation method is easy to operate, adopts the easily-available and low-price raw materials, has a low cost, and increases the purity of products. The titanate nanotube is applied as the electrode membrane material in the lithium ion battery, and has higher specific charge/discharge capacities and better circulation stability.