The development of solid oxide fuel cell (SOFC) operated at low and intermediate temperatures is limited by the poor performance of inorganic ionic conductors. Oxide-based ion conductors have attracted much attention due to their excellent stability and tunable ion conduction behavior. In this study, we propose a new approach for the construction of regulated ionic transport pathways in a composite oxide ionic conductor made of WO3/ZrO2 (WZ) and (Li0.68K0.32)2CO3. The interfacial reaction between WO3/ZrO2 and (Li0.68K0.32)2CO3 is used to enhance the interaction between the oxide and carbonate interfaces and introduce hydrophilic phases for water retention, thus achieving ultra-high ionic conductivity of the oxide/carbonate composites at low and intermediate temperatures. The optimal ionic conductor, 13WZ-30(Li0.68K0.32)2CO3 (13WZ-30C), has a superior ionic conductivity of 25.8-6.28 mS cm−1 from room temperature to 250 °C. The ion conduction mechanism of the composite is investigated. This study emphasizes the significance of interfacial chemistry regulation between oxides and carbonates for achieving superior ion conduction performance.