La₂Ce₂O₇ exhibits intense absorption ability in the ultraviolet (UV) region with excellent photostability, and can replace TiO₂ and ZnO as an UV absorber in sunscreen formulations. Traditionally, La₂Ce₂O₇ powder is synthesized by the solid-state method, which has problems such as high synthesis temperature, small specific surface area of the powder, and poor light absorption ability. In this study, La₂Ce₂O₇ powder was successfully synthesized by a sol-gel method with metal nitrates, citric acid and ethylene glycol as raw materials, chelating agent and stabilizer, respectively. The conversion process of the precursor, phase change of the product, morphology of the powder, and the valence state of the elements were analyzed by TG-DSC, XRD, SEM and XPS. The UV absorption performance of the product was tested using a UV-visible spectrophotometer. The photostability of the product was evaluated by photocatalytic degradation of Rhodamine B dye. The results show that pure phase La₂Ce₂O₇ powder can be synthesized by the sol-gel method at 250 ℃, which is more than 1000 ℃ lower than that of the traditional solid-state method. The maximum specific surface area of the La₂Ce₂O₇ powder synthesized by the sol-gel method is 10.04 m²/g, while that of the powder synthesized by the solid-phase method is only 0.19 m²/g.The La₂Ce₂O₇ powder synthesized at 300 ℃ shows the best UV absorption performance, 25% higher than that synthesized by the solid-state method. Compared with TiO₂, La₂Ce₂O₇ exhibits better UV absorption performance and almost no photocatalytic activity.