In the study, the hierarchical nanohybrid ([email protected]) with mesoporous MCM-41 nanospheres covalent assembling on graphene oxide (GO) nanosheets was successfully prepared, aiming to improve fire retardancy of epoxy resin (EP). Fourier transformation infrared spectra (FTIR), Raman spectra, X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) verified [email protected] The nano-dispersion of [email protected] in EP was certified via TEM and XRD. Fire-retardant investigation (cone calorimeter test) revealed that EP nanocomposite with 2 wt% [email protected] possessed a 40.0% drop of peak heat release rate (pHRR) and suppressed smoke production relative to EP/GO. Intriguingly, EP/[email protected] demonstrated lower pHRR than EP/GO-MCM-41 (direct addition of GO and MCM-41). TG analysis indicated [email protected] imparted EP with significantly reduced degradation rate and increased char yield, accompanied by reduced volatile in thermogravimetric analysis couple with Fourier transformation infrared spectra (TG-FTIR) and improved aromatization in variable-temperature FTIR. The impact strength of EP/[email protected] was enhanced by 38.8% compared with EP. Contrastive analysis proposed the mechanism of neighboring synergy of GO and MCM-41, which involved in GO nanosheets wrapped by enormous carbonaceous stuffs due to MCM-41 neighboring catalysis. In perspective, hierarchical nano-assembly with neighboring synergy offered a viable approach for fire-safe polymers.