The invention discloses a high-efficiency preparation method for a nitrogen-doped titanium dioxide film. The method comprises the steps that (1) a glass substrate is cleaned and then blow-dried by using high-pressure N2; and (2) the nitrogen-doped titanium dioxide film is deposited by adopting a direct-current coupling radio-frequency magnetron sputtering method, namely, a radio-frequency power supply is connected to a matcher and then together with a direct-current power supply is connected to a wave filter, wherein the wave filter is directly connected to a cathode, and the radio-frequency power supply and the direct-current power supply are used for supplying power to the cathode. According to the high-efficiency preparation method of the nitrogen doped titanium dioxide film, the nitrogen-doped titanium dioxide film is deposited by adopting the direct-current coupling radio-frequency magnetron sputtering method so that the film with a high deposition rate and high film quality can be obtained, the technology is simple, the conditions are easy to control, the preparation period is short, scale preparation is easy, and the prepared nitrogen doped titanium dioxide film is high in crystallinity, firm in combination with a substrate, good in stability and reusable.