Photocatalysis, as a new environmentally friendly green technology, has great potential in areas such as environmental remediation and clean energy production. The selection of efficient and economical photocatalytic materials is the key to achieving efficient photocatalytic technology. And bismuth molybdate nanomaterials have attracted much attention from the academic community due to their unique layered structure. This paper reviews the research progress of bismuth molybdate nanomaterials in the field of photocatalysis, mainly from the aspects of bismuth molybdate crystal structure, preparation methods and common modifications. The applications of bismuth molybdate in photocatalysis are highlighted, including photocatalytic CO2 reduction, photocatalytic degradation of organic pollutants, photocatalytic hydrogen precipitation, and photocatalytic nitrogen fixation. The challenges and prospects of bismuth molybdate nanomaterials in photocatalysis have also been explored, providing new ideas for the study of bismuth molybdate photocatalytic materials.