Atmospheric‐pressure (AP) linear cold plasma CVD is employed to deposit TiO2 photocatalytic films uniformly on a moving substrate. The in‐plane and in‐depth uniformities of the as‐deposited TiO2 films are investigated by scanning electron microscopy (SEM) and UV‐vis spectroscopy. The chemical binding states and compositions of the as‐deposited TiO2 films are characterized by X‐ray photoelectron spectroscopy (XPS). Raman, X‐ray diffraction (XRD), and Fourier transform infrared (FTIR) spectra prove the structures of the as‐deposited and calcined TiO2 films are mainly hydro‐oxygenated amorphous (a‐TiOx:OH), and exclusively anatase, respectively. The photocatalytic activity of the as‐deposited and calcined TiO2 films is evaluated in a continuous flow reactor for HCHO removal with simulated air. The activity of the as‐deposited TiO2 films increases with film thickness, leveling off at about 780 nm. The activity of the as‐deposited TiO2 film is lower than that of the calcined one.