The invention provides a method for preparing a Y/Sm2O3/SBA-3/ASA composite material containing regular mesopores. The method comprises the following steps: preparing a guiding agent, preparing an Sm2O3/SBA-3 precursor, and synthesizing a Y/Sm2O3/SBA-3 composite molecular sieve from the reaction mixture by adopting a hydrothermal crystallization method; adding a surfactant and an alkaline aluminum-source solution into the Y/Sm2O3/SBA-3 composite molecular sieve slurry, and adjusting the pH value to obtain a solid product; and washing, drying and roasting the product to obtain the Y/Sm2O3/SBA-3/ASA composite material of which the surface is coated with ASA. In the composite material, the differential thermal failure temperature of the Y-shaped molecular sieve can be higher than 950 DEG C, and the grain size is kept to be lower than 400nm. The composite material has the porous distribution characteristics of micropore-mesopore, mesopores in the surface ASA are regular mesopores, and the mesoporous size can be adjusted by changing the synthesizing process condition.