Hydrogen energy is a kind of novel green energy due to its special characteristics, such as clean property, and etc. And its production through photoelectrolysis of water by utilizing the solar energy also exhibits good application prospect. The fundamentals of photoelectrolysis water splitting by the aid of TiO2 are summarized. Many factors can affect photoelectrocatalysis hydrogen production efficiency, and much attention is paid to the effect of semiconductor flatband potential and the performance of TiO2 film on the hydrogen evolution efficiency. Methods of applying external bias potential and principles of modification methods are also briefed. At last, some basic problems about photoelectrocatalysis hydrogen production that still unresolved efficiently so far are pointed out, and its application prospect is viewed.