Solar-energy-driven photocatalytic water (H2O) splitting converts solar energy into a high-valuable chemical, i.e. hydrogen (H2), and is thereby a promising technique for achieving a sustainable society. However, photocatalytic H2O splitting have not been applied at a scalable industrial level yet. In addition to photocatalyst, reactor is also a crucial factor affecting efficiency of photocatalytic H2O splitting. There are a large number of works focusing on photocatalytic H2O splitting, including both reviews and research works. However, the reported works on photocatalytic H2O splitting paid little attentions on reactor. Herein, we discuss recent progresses on reactor for photocatalytic H2O splitting, and highlight challenges for further studies. This is helpful for further improving efficiency of photocatalytic H2O splitting.