A ternary heteropoly acid (HPA) H6SiW[Formula: see text]V2O[Formula: see text]14H2O was prepared and investigated in this paper. The structure feature and hydration of this HPA was characterized by IR, XRD, UV, and TG-DTA. This HPA exhibits a high proton conductivity, which is [Formula: see text]S[Formula: see text]cm[Formula: see text] at 25[Formula: see text]C and 70% relative humidity. It is a novel high proton conductor. The conductivity increases with higher temperature, and it exhibits Arrhenius behavior, with the activation energy value of 21.02[Formula: see text]kJ[Formula: see text] mol[Formula: see text] for proton conduction, indicating the proton conduction mechanism is dominated by vehicle mechanism.