In order to improve the surface loading capacity, the adsorption capacity and thermal insulation properties of ceramic foams, mullite ceramic foams (MCFs) with different mullite whisker content by impregnating NH4F solution with high specific surface area and high surface roughness prepared. The filtration effect of different MCFs on Fe2O3 turbid liquid was tested and compared by a specific experimental device, and MCFs with 100 % mullite whisker content showed 250 % adsorption capacity compared to MCFs without mullite whiskers. The phase composition and microstructure of MCFs were characterized by XRD and SEM. The bulk density, true density, total porosity, thermal conductivity and compressive strength of different MCFs were compared. In this study, MCFs with 100 % mullite whisker content had the highest compressive strength of 26.15 MPa and the lowest thermal conductivity of 0.17–0.23 W/(m·K) (200–800 °C).