Abstract: Improving the photocatalytic catalytic efficiency of TiO₂ was one of the hot spots in the current research. This paper summarized the principle of photocatalytic reaction, analyzes the factors affecting the photocatalytic efficiency of TiO₂, provides ideas to improve the photocatalytic efficiency of TiO₂ from the perspectives of material modification and the design of photocatalytic reactor, and looked forward to the future development of photocatalytic materials and photocatalytic reactor.