H6P2W18O62/TiO2-SiO2 was prepared by using impregnation method and characterized by FI-IR, XRD and SEM. Through the study of methyl orange with H6P2W18O62/TiO2-SiO2, the optimal conditions found are as follows: H6P2W18O62 loading dosage is 30%, calcination temperature was 200 ℃, calcination time is 3 h. Its activity for photocatalytic degradation of methyl orange in dye waste water was investigated. The influence of initial concentration of methyl orange, catalyst dosage and pH value of solution on photocatalytic degradation efficiency was studied. The reuse of the catalyst was discussed. The results indicate that H6P2W18/TiO2-SiO2 photocatalysts exhibit superior photocatalytic performance, when catalyst dosage is 1.39 g /L and initial concentration of methyl orange is 5 mg /L in the pH=3.5 and the reaction time is 2.5 h under the optimum conditions, the degradation rate of photocatalytic methyl orange is 99.2% and produced a synergistic effect. The photodegradation of methylene blue, rhodamine B and methyl red were also show superior photocatalytic performance, and the degradation rate of dyes can reach 84.0%~100.0%. Photocatalyst also exhibited good reusability and the degradation rate for methyl orange still kept at 94.4% after 5 runs.