In this paper, calcium hexaaluminate (CA6) porous ceramics were prepared by a foaming method combined with cement solidification molding. The effects of the foaming agent addition on the microstructure and the properties of the ceramics were studied. The results show that the microstructure and the porosity of the ceramics can be controlled by adjusting the addition of the foaming agent. As the addition of the foaming agent increased, the bulk density reduced from 1 g · cm^-3 to 0.35g · cm^-3, the porosity increased from 70.4% to 89.6%, the compressive strength reduced from 18.46 MPa to 1.66 MPa, and the thermal conductivity at 1 000 °C decreased from 0.382 W · m^-1 · K^-1 to 0.144 W · m^-1 · K^-1. It is indicated that calcium hexaaluminate porous ceramics with low density, high strength and low thermal conductivity can be obtained by the foaming method. As the lining material of high temperature electric furnaces, the ceramic has excellent energy saving effect.