Semiconductor photocatalytic water splitting has been considered as a potential strategy to overcome global energy shortage and environmental pollution. In recent years, phosphorene (BP) attracted great attention in photocatalytic water splitting due to its adjustable band gap, high hole mobility and wide absorption spectrum. This review summarizes the recent significant advances on designing high-performance BP-based photocatalysts for water splitting. The synthetic methods and modification strategies (e.g., surface modification and heterostructure design) of BP-based photocatalysts are described. Furthermore, in order to elucidate the structure-activity relationship of BP-based photocatalysts, the charge transfer mechanism is illustrated. Finally, the ongoing challenges and opportunities for the future development of BP-based photocatalysts in the exciting research area are highlighted.