Copper ion was added in liquid feedstock to deposit ion doping TiO2 photocatalytic coatings through liquid flame spraying. The coating microstructure was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The photocatalytic performance of coatings was examined by photodegradation of acetaldehyde. XRD analysis shows that the crystalline structure of coatings is not significantly influenced by the metal ion doping. The photocatalytic activity of the TiO2 coatings is enhanced by the copper ion doping. It is found that a high concentration of ion doping decreases the activity. XPS analysis shows that the adsorbed oxygen concentration is increased with the increase of Cu2+ dopant concentration and decreases with the further increase of dopant concentration. The enhancement of photocatalytic activity can be attributed to the adsorption ability of oxygen and other reactants on the surface of doping TiO2 coatings.