A mesoporous zinc ferrite decorated graphene oxide (MZF-GO) nanohybrid was prepared through a one-step solvothermal method and well characterized, with the aim of reducing fire hazards of epoxy resin (EP). Results show that the LOI value of the EP filled with 3 wt % MZF-GO is 27.2, much higher than that of the EP (22.1). Simultaneously, in comparison with the EP, the peak heat release rate, total smoke release, and the peak CO productive rate of the MZF-GO/EP nanocomposite are reduced by 39.57%, 32.56%, and 58.80%, respectively. This is attributed to the synergistic flame-retardant effect between GO and MZF. Namely, GO can act as the physical barrier to block the release of combustible gases and the transfer of heat energy and oxygen, while MZF can catalyze the cross linking of macromolecules and promote the char formation of EP and absorb inflammable gas and heat.