Abstract: Ni(OH)₂/graphitized carbon nitride(g-C₃N₄)/reduced graphene oxide (RGO) ternary synthetics were prepared by a hydrothermal method. The effect of different mass ratios of the three components on the microstructure, morphology and electrochemical properties of the synthetics was investigated. The outside microstructure and extent of redox of the material were characterized by XRD, SEM, FTIR, nitrogen adsorption and TEM. The composite properties of the synthetics were examined use cyclic voltammetry(CV), galvanostatic charge-discharge(GCD) and electrochemical impedance spectroscopy(EIS). The consequences reveal that the ternary composite represents three-dimensional slice space interlaced structure when the quality proportion of Ni(OH)₂, g-C₃N₄ and RGO are 16∶1∶1, and the ΔE is 0.218 V. When the current density is 1 A/g, the specific capacitance of the synthetic material is 516.9 F/g. After 3 000 cycles of charge-discharge, the capacity retention rate is 74.3%, which revealedoutstanding electrochemical performance.