By using hydrothermal and spin-coating method, Ti mesh supported composite structure, TiO₂ nanowire arrays/Yb-Er-F doped TiO₂ upconversion luminescence nanoparticles (TNWAs/YEF-TiO₂-UCNPs), was synthesized and assembled into flexible dye-sensitized solar cell (DSSC). The effect of YEF-TiO₂-UCNPs optical property on the power conversion efficiency (PCE) of this device was studied. In addition, the influence of NbCl₅ solution coating on morphology and performance of flexible DSSC was also investigated in detail. It is shown that the YEF-TiO₂- UCNPs could expand the range of incident light utilization, in the meantime, however, increase the electron recombination in photoanode. Nb₂O₅ coating layer served as an energy barrier at the semiconductor/electrolyte interface, increased the composite resistance R_rec to inhibit electron recombination, improved the electron collection efficiency η_ec and photogenerated electron lifetime τ_e, then elevated the short circuit current and the open circuit voltage, finally enhanced the performance of DSSC. The Nb₂O₅@TNWAs/YEF-TiO₂-UCNPs composite structured DSSC achieved the best PCE of 6.89% with 20 mmol/L NbCl₅ ethanol solution coating, increased 24.3% compared with the uncoated blank device.