N-doped titanium dioxide (TiO${}_2)$ hollow nanospheres with abundant oxygen vacancies were successfully synthesized by coupling urea treatment and annealing in an N₂ atmosphere. The pristine TiO₂ hollow nanospheres exhibit a shallow donor level for electron trapping, while the urea treatment generates a N 2p acceptor level for hole trapping. After annealing in N₂, the sufficient N atoms generate abundant oxygen vacancies for trapping electrons, resulting in further improved charge separation efficiency. The N-doped TiO₂ exhibits the highest H₂ evolution rate, reaching 2867$$$\mu$mol$$g${}^{?1}$$$h${}^{?1}$, which is six times higher than that of pristine TiO₂ hollow nanospheres. The introduction of oxygen vacancies by interstitial N provides a promising way to improve the photocatalysis activity of photocatalysts.