The invention belongs to the technical field of photoelectrochemistry and photovoltaics and in particular provides a tungsten-doped nanocrystalline titanium dioxide semiconductor film as well as a preparation method and an application thereof. The method is characterized by firstly adding tungstic acid solution to titanium isopropoxide, obtaining a tungsten-doped titanium dioxide colloid through treatment in water and then forming the nanocrystalline film through a hydrothermal method. The film and the preparation method have the following beneficial effects: the conduction band energy level of the titanium dioxide can be regulated after the tungsten is doped to ensure the conduction band energy level to be better matched with the excitation state energy level of the dye; the short circuit photocurrent and electron life of a dyed sensitized solar cell can be obviously improved when the nanocrystalline film is used for assembling the cell, thus substantially improving the energy conversion efficiency; and the defect that some dyes are unmatched with the conduction band energy level of the titanium dioxide can be overcome, and the preparation method has a good application prospect.