Owing to the much concern with global environmental problem, photocatalytic TiO2 coatings were obtained using plasma spraying technique. The influences of the content of Fe3O4 additive to the TiO2 powder on the phase composition, microstructure and photo-absorption of plasma sprayed TiO2 coatings were systematically studied. The photocatalytic efficiency of the sprayed coatings is evaluated through the photo mineralization of acetaldehyde. The UV-VIS-NIR absorption spectra of the deposited coatings were obtained by using Shimadzu UV-3100PC scanning spectrophotometer. The results showed that the TiO2-Fe3O4 coatings consist of anatase TiO2, rutile TiO2 and FeTiO3 ilmenite, and Fe2TiO5 pseudobrookite phase appears when the content of Fe3O4 additive is equal to or over 10%. The content of anatase TiO2 in the sprayed coatings decreases from 14.8% to 5.9% with the increasing of Fe3O4 content to 32.6%. It was found that TiO2 coatings can decompose acetaldehyde under the illumination of ultraviolet rays, and the degrading efficiency is improved with an increase in the content of FeTiO3 in the coatings. However, the presence of large amount of Fe2TiO5 compound will substantially lower the photocatalytic efficiency of the sprayed TiO2-Fe3O4 coatings for the unfavorable photo-excited electron-hole transfer process.