In this study, we analyzed the growth and annealing parameters of TiO2 nanotube (TNT) arrays and their effect on C14H14N3NaO3S methyl orange degradation. At first, the TNT arrays were grown on Ti metal by the anodic oxidation method under DC voltages of 10–30 V. Surface observation was used to judge the effect of the grown TNT arrays, and we found that 20 V was the optimum voltage in this study. After the TNT arrays were grown under the DC bias of 20 V, the TNT arrays were annealed at temperatures in the range of 400–500 ℃ for time durations of 1–3 h. From the X-ray diffraction (XRD) patterns, we found that the as-grown TNT arrays have an amorphous phase. Because different annealing temperatures and annealing times were used, the XRD patterns showed that only the anatase TiO2 phase and Ti phase were observed. The TNT arrays with different annealing parameters were used to carry out experiments on C14H14N3NaO3S methyl orange degradation. The transmittance spectra of C14H14N3NaO3S methyl orange has one strong and wide absorption band located at 463–464 nm and a small absorption band located at 270–271 nm. The C14H14N3NaO3S methyl orange solutions under only UV-light irradiation were almost unchanged with the increase in irradiation time. After the annealed TNT arrays were used to degrade the C14H14N3NaO3S methyl orange, we found that the TNT arrays grown at 20 V and annealed for 1 h at 450 ℃ had the best effect on the C14H14N3NaO3S methyl orange degradation.