Pr3+:Y2SiO5/ZnO-TiO2/ACF composites were prepared by sol-gel technique of anchoring ZnO and upconversion fluorescent material/TiO2 nanocomposites on activated carbon fiber(ACF). The properties of samples were characterized by XRD, SEM, EDS, FS, and UV-vis DRS. The photocatalytic activity of Pr3+:Y2SiO5/ZnO-TiO2/ACF was evaluated for degradation of methylene blue solution under visible light irradiation. The effect of ZnO mass doping concentration on photocatalytic activity of composites was investigated. The results showed that Pr3+:Y2SiO5/ZnO-TiO2/ACF showed the highest visible-light photocatalytic activity in the degradation of methylene blue (500mL, 15mg/L), when the mass fraction of ZnO doping was 10%. After 12 h, the degradation of methylene blue can be as high as 98.0%. The photodegradation followed pseudo first order process and reaction rate constant is 0.3413 h-1, which is 1.7 times as high as Pr3+:Y2SiO5/TiO2/ACF. The removal rate of methylene blue for Pr3+:Y2SiO5/ZnO-TiO2/ACF could be remained above 85% after recycling four times.