Ceramic foams is a kind of inorganic non-metallic material with a three-dimensional porous network structure after calcination at high temperatures. The mechanical properties are one of the important factor to evaluate the application of ceramic foams, which affected by the porosity, pore size, pore distribution and skeleton structure, etc. High porosity would reduce the bearing capacity of ceramic foams and limit its application fields. Therefore, this research is mainly focused on how to balance porosity and strength of ceramic foams, as compressive strength could be improved effectively by reducing the pore size, narrowing the pore size distribution or forming a closed pore structure.When coal gangue is used as raw materials to prepare ceramic foams, it still exists some problems, such as the low utilization, high energy consumption and unclear foaming principle. The key to producing a ceramic foam is to form a melt matrix with appropriate viscosity and to generate a certain amount of foaming gas in the matrix. Due to the complex composition of coal gangue,it is difficult to control the viscosity of the melt matrix at high temperatures, resulting in the pore structure distribution uneven and reducing the mechanical properties of ceramic foams.In this work, coal gangue was used as the main raw materials, and diatomite powder, talc powder, a small amount of silicon carbide (SiC) foaming agent were added to prepare the ceramic foams with high compressive strength. The effects of raw materials composition, SiC content (mass fraction) and particle size of feed mixture on the pore structure, apparent density and compressive strength and other properties of ceramic foams were investigated.