TiO2 is a promising photocatalyst due to its excellent photocatalytic activity, physical and chemical stabilities. Plasma spraying technology is good way to prepare for TiO2 coating. The effect of spraying parameters on photocatalytic performance was studied. The results showed that both the amount of unmelted particles and the porosity of as-sprayed TiO2 coatings increased with the increasing of Ar gas flow rate. And the external bias could improve TiO2 coating’s photocatalytical performance. The improvement degree is closed related its grain size and porosity.