Photocatalyst Bi3O4Cl was successfully prepared using Bi(NO3)3·5H2O as a bismuth source through one-pot hydrothermal method. The as-synthesized samples were characterized by the means such as XRD, SEM, and UV-Vis DRS and took Rhodamine B as target degradation substance to study the property of photocatalyst of Bi3O4Cl.The result indicated that the photocatalytic efficiency is greatly affected by hydrothermal temperature, and the sample Rhodamine B synthesized at hydrothermal temperature 90℃ exhibits satisfactory photodegradation performances, witch mainly attributes to small band width and strong adsorption ability on RhB.The experiment provides a kind of new novel method of photocatalyst Bi3O4Cl and contribute to the application and development of photocatalyst technology in control field of environment pollution.