Abstract: In recent years, water-zinc ion batteries have been widely concerned in the new energy storage system in the post-lithium era due to their advantages of low cost, abundant resources, and high theoretical capacity of the zinc negative electrode. However, finding suitable cathode materials is the key and challenge in the development of zinc-ion batteries. Polyoxomethanate （abbreviated as polyacids） are considered to be a highly promising electrode material due to their high redox activity and multi-electron transfer characteristics. However, issues such as easy dissolution, easy agglomeration, and poor conductivity of polyacids have hindered their application in the energy storage field. In order to solve these problems, polyaniline （PANI） was in-situ grown on the surface of graphene oxide （GO） as the substrate, and Keggin-type polyacid H₃PMo₁₂O₄₀ was supported by electrostatic interaction. Finally, the rGO-PANI-PMo₁₂ （GPM） composite materials were prepared. The intention of this work was to utilize graphene and its surface functional groups to improve the immobilization, dispersibility, and conductivity of polyacids. The characterizations of XRD, FTIR, SEM, TEM, XPS, and electrochemical performance tests were used to explore the influence of the ratio of GO and ANI on their morphology, structure, and electrochemical performance. The results showed that when the mass ratio of GO to ANI was 1∶20, the prepared GPM material exhibited both high redox activity of polyacids and high conductivity of graphene, having a high discharge specific capacity of 258 mAh/g at 0.2 A/g, and a capacity retention rate of 82.2% after 1000 cycles at 2 A/g, demonstrating good cycle stability. In addition, the results of reaction kinetics studies indicate that the electrochemical reaction process of the GPM electrode is controlled by both diffusion and capacitance, thus exhibiting a faster Zn²⁺ diffusion rate and charge transfer rate.