A carbon nanotube aligned film as well as a preparation method and application thereof are disclosed. The preparation method includes: providing a carbon nanotube dispersion solution comprising a selected carbon nanotube, a polymer as a carbon nanotube dispersing agent and binding to the selected carbon nanotube, an aromatic molecule binding to the selected carbon nanotube and allowing the surface of the selected carbon nanotube to have the same charges and an organic solvent being at least used for cooperating with the rest components of the dispersion solution to form uniform dispersion solution; and introducing a water phase layer to the upper surface of the dispersion solution to form a double-layer liquid phase system, partially or completely inserting a base into the double-layer liquid system, and then pulling out the base so as to form the carbon nanotube aligned film on the surface of the base.