Blast furnace slag is a type of bulk solid waste generated by the iron and steel industry. The high value-added utilization of blast furnace slag has been the focus of research in the relevant industries, which is of great significance to the green development of the steel industry. This work focuses on blast furnace slag and reviews the progress of its use as a photocatalytic material for wastewater treatment in the last five years. Firstly, we introduce the basic information of blast furnace slag, such as the formation and mineral composition of blast furnace slag, the feasibility of using it as a photocatalytic material, the current situation of comprehensive utilization at home and abroad, and the problems in comprehensive utilization. Secondly, the current status of photocatalytic technology is briefly explained, covering its mechanism of action, performance improvement methods and development trends. Then, the progress of research on blast furnace slag as a photocatalytic material for wastewater purification is described. The existing literature on the factors affecting its photocatalytic efficiency and ways to improve it are discussed. Finally, the treatment and application of blast furnace slag-based photocatalytic materials are summarized, and its sustainable resource utilization is also prospected.