In order to prepared the phenolic foams with excellent cell structure and mechanical properties, the graphene/silica (GNPs/SiO₂) hybrid materials were prepared by the method of in situ formation. The graphene and GNPs/SiO₂ hybrid materials were used in the preparation of phenolic foams. The cells structure and compression properties of the phenolic foams were analyzed,and found that hybrid materials can improved the bubbles structure and mechanical properties more effectively. and the Infrared Spectroscopy(FT-IR),transmission electron microscopy (SEM) and X-ray diffraction (XRD) analysis were conducted and confirmed the silica spheres were formed on the surface of the GNPs. The silica shows a particle size of 150-180nm. The phenolic foams showed more uniform cell structure and small cell size when the content of hybrid materials was 0.5wt%. GNPs/SiO₂ modified phenolic foams showed the excellent mechanical properties than the graphene modified phenolic foams. The compressive strength and modulus of 0.5wt% graphene/SiO₂ modified phenolic foams was 0.22 and 4.11MPa, which has increased by 91% and 86%, respectively, compared to the pure phenolic foams.