CsLaTa2O7/Na2Ta2O6 heterostructure photocatalyst was constructed via the growth of pyrochlore⁃type Na2Ta2O6 particles on the surface of layered structure CsLaTa2O7 using its metastable property through hydrothermal method. The CsLaTa2O7/Na2Ta2O6 was characterized by XRD, SEM, TEM, UV⁃Vis spectroscopy and PL spectroscopy. The results show that the CsLaTa2O7/Na2Ta2O6 heterostructure can effectively inhibit the recombination of photogenerated electrons and holes, and its photocatalytic performance under UV light is significantly higher than that of single phase. Methylene blue can be completely degraded within 10 min under the illumination of ultraviolet light.