Semiconductor oxide photocatalysis to purify contaminants has drawn more attention and formed a flourishing research part in materials as well as in environmental science. In this paper, we presented the results of photocatalytic experiment involving a series of semiconductor oxide thin films mixed with TiO2 and WO3, immobilized on glass plates by reactive sputtering method, The degradation was carried out in dyeing waste water to investigate the effect of film structure and semiconductor properties on photocatalysis. The film structure and properties were studied by means of TEM and UV transmission spectra. The experimental results of photocatalytic degradation revealed that nanocrystalline/nanoporous structure could enhance the efficiency of photocatalysis and the effectiveness of decomposition reactions increased with the content of crystalline (anatase) phase in TiO2 thin films, meanwhile, the properties also had regular effect on photocatalytic efficiency. The similar researches were done for WO3 films. In addition, photocatalytic degradation mechanism was analyzed based on experimental results.