Perovskite-type catalysts show promising potential in the purification of automobile exhaust. This paper discussed the synthesis of mesoporous material COK-12 using surfactant P123 as a soft template and inexpensive sodium silicate as the silicon source under nearly neutral conditions. Building on this, the mesoporous COK-12 was modified with p-xylene as a swelling agent, resulting in large-pore, ordered mesoporous materials. Subsequently, for the first time, modified mesoporous materials were used as templates for the preparation of mesoporous La0. 8 Sr0. 2 MnO3 catalysts through nano- casting combined with the sol-gel method. The results demonstrate that the catalyst synthesized at 550 ℃ possesses a larger specific surface area (72. 11 m2 / g) and the highest molar ratio of Mn4 + / Mn3 + and Oads / Olat on the surface. Additionally, CO catalytic performance tests of samples indicate that those synthesized at 550 ℃ exhibit the best catalytic activity and excellent high-temperature stability. Their characteristic temperatures T50 and T90 are 180 and 218 ℃ , respectively.