Aqueous zinc ion battery (ZIB) with many virtues such as high safety, cost-effective, and good environmental compatibility is a large-scale energy storage technology with great application potential. Nevertheless, its application is severely hindered by the slow diffusion of zinc ions in desirable cathode materials. Herein, a technique of water-incorporation coupled with oxygen-vacancy modulation is exploited to improve the zinc ions diffusion kinetics in vanadium pentoxide (V₂O₅) cathode for ZIB. The incorporated water molecules replace lattice oxygen in V₂O₅, and function as pillars to expand interlayer distance. So the structural stability can be enhanced, and the zinc ions diffusion kinetics might also be promoted during the repeated intercalation/deintercalation. Meanwhile, the lattice water molecules can effectively enhance conductivity due to the electronic density modulation effect. Consequently, the modulated V₂O₅ (H-V₂O₅) cathode behaves with superior rate capacity and stable durability, achieving 234 mA h g⁻¹ over 9000 cycles even at 20 A g⁻¹. Furthermore, a flexible all-solid-state (ASS) ZIB has been constructed, exhibiting an admirable energy density of 196.6 W h kg⁻¹ and impressive power density of 20.4 kW kg⁻¹ as well as excellent long-term lifespan. Importantly, the assembled flexible ASS ZIB would be able to work in a large temperature span (from −20 to 70 °C). Additionally, we also uncover the energy storage mechanism of the H-V₂O₅ electrode, offering a novel approach for creating high-kinetics cathodes for multivalent ion storage.