N-doped TiO2 nanoparticles supported TiO2 film was fabricated on the FTO substrate by a dip-coating method. The influence of N-doped TiO2 nanoparticles on the film composition, microstructure, light absorption capability and electron hole migration property were characterized by XRD, XPS, TEM, SEM, AFM, Raman spectroscopy, UV-Vis spectroscopy and PL spectroscopy. The corresponding photocatalytic properties in photoelectrochemical oxygen production and photocathodic protection have been investigated. The results indicated that the N-doping led to the intermediate energy level formation above the top of O-2p valence band, which extended the photo response of TiO2 to the visible light range and promoted the electron-hole separation. Furthermore, the addition of N-doped TiO2 particles to TiO2 sol essentially improved the continuity of TiO2 film, resulting in effective inhibition of the corrosive ions migration to the stainless steel substrate.