Graphene oxide (GO) can be used as surfactants in numerous technological fields. For this study, functionalized GO was used as a novel reactive compatibilizer with large surface area to compatibilize immiscible polymer blends. The compatibilizer is composed of three parts with non-polar polymer chain, polar segment and GO sheet, which appears to be of more practical significance and can greatly expand the compatibilizing range. Monomer casting nylon (MC nylon)/polyethylene-octene elastomer (POE) was chosen as the immiscible polymer pairs to investigate the compatibility and comprehensive properties of the compatibilizer. With the incorporation of the novel reactive compatibilizer (GO-TEPAF-POE), the immiscible blends exhibited better compatibility and the dispersion of the minor phase (POE) is remarkably improved without obvious agglomerates. Moreover, GO-TEPAF-POE also acts as multifunctional fillers for MC nylon/POE blends, thus enhancing their mechanical properties and thermal stability. In particular, the notched impact strength values sharply increase by 84 % as opposed to the neat MC nylon. The novel compatibilizer with large surface area may broaden its potential application and fully exploits the extraordinary properties of these appealing carbon nanomaterials.