The work aims to prepare TiO2 and Si-doped TiO2 coatings by solution precursor plasma spraying and respectively investigate effects of H2 flow and Si doping on photocatalytic performance of TiO2 coatings. The crystal phase, surface morphology and chemical structure of the samples were characterized by X-ray diffraction, scanning electron microscopy, Raman spectroscopy and Fourier transform near-infrared spectroscopy. The photocatalytic performance of TiO2 and Si doped TiO2 coatings was tested with photochemical reactor by using methyl orange as the target compound to simulate organic pollution. Appropriate amount of doped Si could refine the grains, increase the content of anatase phase in TiO2 coating (from 7.4% to 49%) and form Ti—O—Si bonds. The degradation rate of Si doped TiO2 coatings was up to 95% and higher than that of pure TiO2 coating as 80%. With the increase of hydrogen flow rate, the crystal grains of TiO2 coating obviously roughened and mainly existed in the form of rutile phase. The degradation rate of methyl orange in TiO2 coating with hydrogen flow rate of 8 L/min reached 82% which was much higher than 52% and 33% for hydrogen flow rate of 4 and 10 L/min. The photocatalytic performance of Si-doped TiO2 coating is better than that of pure TiO2 coating. The photocatalytic performance is the best when the hydrogen flow rate is 8 L/min.