TiO2-loaded activated carbon fiber (TiO2/ACF) was prepared by using the residue after epoxy was calcined as the link between TiO2 and activated carbon fibers. The effect of pore size on the photocatalytic activity of TiO2/ACF was investigated. For large β-cyclodextrin molecules, it was found that an increase in pore size favored high photocatalytic activity; the photocatalytic activity achieved at the optimal pore size also did not decline when the sample was used repeatedly.