Nitrogen and carbon co-doped porous TiO2 nanofibers (NCPTNs) were exploited by a combination of electrospinning and controlled calcination technologies. Polyvinyl pyrrolidone (PVP) was employed both as a template and as a nitrogen and carbon source. It is clear that the prepared NCPTNs exhibit high absorption in the visible light region, suggesting that the co-doping of nitrogen and carbon onto TiO2 not only leads to a shift of the absorption edge to lower energy by inducing new band levels, but also creates large amounts of single-electron-trapped oxygen vacancy. Besides, the porous structure and high surface area provide large active points for the photodecomposition reaction of methylene blue. Moreover, the NCPTN obtained in 5 wt% urea shows the highest photocatalytic activity for methylene blue decomposition under the visible light irradiation.