Generally, graphene and functionalized graphene are used to re inforce polymers. In this work, functionalized graphene with silane coupling agent was prepared and used as both compatibilizer and reinforce filler to MVQ/PLLA TPV. Neither 3-aminopropyl triethoxysilane functionalized graphene nor 3-aminopropyl triethoxysilane can compatibilizer MVQ/PLLA TPV. But when both of functionalized graphene and silane coupling agent were introduced to MVQ/PLLA TPV, its tensile strength, storage modulus, thermal stability, permitivity and gas impermeability were improved drastically. The synergistic compatibiliztion mechanisms of functionalized graphene and 3-aminopropyl triethoxysilane to MVQ/PLLA TPV were investigated thoroughly.