The photocatalysts TaOxNy were prepared by gas-solid reaction method with Ta2O5 as starting substance nitrified by NH3 under high temperature.The prepared samples were characterized by XRD,XPS,and UV-VIS.The results of XRD and XPS showed that non-stoichiometric sample,TaO1.3N0.8,was formed when the reaction temperature was 850℃,the reaction time was 10 hours and the flux of ammonia gas was 100 mL/min.And the result of UV-VIS showed that the response area of the sample was shifted to the visible-light.In addition,the photocatalytic activities of TaOxNy for degradation of dichloroacetic acid(DCAA)under irradiation of visible light were also investigated in the paper.Furthermore,Pt/ TaOxNy was prepared by loading Pt on the surface of TaOxNy by photoreduction method.And the effect of depositing amount of Pt on degradation of DCAA were also discussed.The results showed that the photocatalytic activities of TaOxNy were highly increased by loading Pt on the surface of TaOxNy.The optimum loading amount of Pt was 1.5wt%.The degradation rate of DCAA was 51.06 % after irradiation for120 min under visible-light.