Nowadays, with the expansion of industries, the need to use industrial adhesives that can create new properties in the final sample while solving problems is felt more and more. Epoxy resins have the ability to be compatible with all kinds of nano fillers due to their extraordinary properties, in addition to providing proper thermal and mechanical resistance. In the present project, after preparing graphene oxide (GO) using the Hammers method and modifying it with the 1,'1-(hexane-1,6-diyl)bis(3-(3-(trimethoxysilyl)propyl)urea) silane modifier (HDBTMSPU), FGO was obtained. After the preparation of FGO, graphene xerogel (GX) was prepared by sol-gel reaction of FGO nanosheets with tetraethyl orthosilica (TEOS) and HDBTMSPU. Epoxy resin was chemically modified by oligomer TEOS and (3-isocyanatopropyl) triethoxysilane (IPTEOS). GX/epoxy nanocomposite (EGX) and silica/graphene/epoxy nanohybrid were prepared using TEOS, FGO and two types of TE and IE resins (TEGX, IEGX) through sol-gel reaction and their thermal properties were evaluated with EGX nanocomposite. The results of the FTIR, XPS and TGA tests showed that graphene and epoxy resin were successfully chemically modified. The structure of GX was investigated by Raman, XRD, SEM and TEM tests. The results obtained from the thermal decomposition test of graphene samples and nanocomposite samples demonstrated that after each step of GO chemical modification, the stability and thermal resistance of nanosheets increased significantly and the thermal properties of prepared nanocomposites were improved compared to epoxy resin.