3-Nitro-1,2,4-triazole-5-one (NTO) is a high-energy insensitive explosive with broad application prospects. However, due to the slow energy release kinetics, high decomposition temperature and unsatisfactory safety performance, its effective application is affected. In this paper, a reduced graphene oxide hydrogel (rGH)/NTO composite material was prepared to improve both the physical and chemical properties of NTO. The morphology and structure of the samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It was found that the rGH/NTO composites did not undergo polymorphic transformation during the preparation process. At the same time, the three-dimensional (3D) network structure formed by rGH can reduce the initial temperature and activation energy of NTO thermal decomposition, and significantly increase the energy release rate. In addition, combined with experiments and DFT theoretical calculations, it is verified that the synergistic effect of the composite material reduces the corrosivity of NTO and increases the insensitivity, thereby improving the effective safety performance. Therefore, the synergistic effect of 3D network structure composite strategy is expected to be extended to the multi-performance control of energetic materials.