With the rapid development of the world economy, serious energy shortages and environmental crises have emerged, and photocatalytic technology is an effective solution to alleviate this problem. Bismuth trioxide, due to its unique layered structure and narrow bandgap, has the potential for visible-light-driven photocatalytic performance and has gradually become one of the recent research hotspots in the field of environmental energy science. This paper outlines the current research status of bismuth trioxide photocatalytic materials, and describes their construction strategies, removal effects and main mechanisms. Its applications in environmental energy fields such as photocatalytic water environment treatment, hydrogen production by water decomposition, nitrogen fixation and desulfurisation, bactericidal disinfection, carbon dioxide reduction, battery electrode, etc., are also described and prospected.