Photocatalytic reactions can convert solar energy into storable chemical energy, thus providing a feasible strategy for solving energy crisis and environmental problems. However, the photochemical conversion efficiency is restricted due to the low transfer and separation efficiency of photogenerated carriers. The emerging S-scheme heterojunction photocatalysts have attracted recent attention in the fields of solar fuel conversion and environmental purification for the spatially efficient separation of photogenerated carriers and strong redox ability. This review represented recent development on the design principles, charge transfer mechanism and applications of S-scheme heterojunction photocatalysts. In addition, their prospects and challenges were also discussed.