The bilayered vanadium pentoxide (δ-V₂O₅·nH₂O, VOH) is the most promising cathode material for aqueous zinc ion batteries due to its high theoretical capacity, low-cost, and easy preparation. However, the capacity decay arising from the structure instability remains a significant challenge for the application of VOH. The present study focuses on stabilizing the VOH structure via pre-intercalation of Na⁺ cations into the bilayers, which occurs by replacing the partial interlayer water. Though has a smaller interlayer spacing, the Na⁺ intercalated vanadium oxide (δ-Na_0.27V₂O₅·0.7H₂O, NaVOH) delivers a large specific capacity of 420 mA h/g (at 0.05 A/g), with improved energy efficiency, reversibility, and cycling stability (88% capacity retention after 2000 cycles at 4 A/g), in comparison to those of V₂O₅·1.0H₂O. The results reveal that Na⁺ions are favorably intercalated within the VOH layers by the spontaneous ion-exchange with structural water. The introduction of sodium cations, an increased amount of V⁴⁺, as well as a reduced interlayer water content in NaVOH collectively result in the fast transport and reaction kinetics as well as the improved structural and electrochemical stability.