<p>Combining nanomaterials with the three-dimensional hydrophilic network of hydrogels is an effective strategy for creating smart materials with enhanced mechanical properties and advanced functionalities. Herein, chitosan quaternary ammonium/polyacrylamide (QP) hydrogels with interpenetrating networks were prepared <i>via</i> an <i>in situ</i> method based on chain entanglement, in which polyoxometalate (POM) nanoparticles were introduced as physical crosslinking agents. This incorporation of POMs significantly improved the overall mechanical properties of the hydrogels, endowing them with high fracture energy, low hysteresis, and outstanding resilience under high water content (&gt;90%). Owing to the strong water molecule adsorption capacity of POMs and their homogeneous and dense distribution as physical crosslinking points in the hydrogel structure, the friction coefficient was significantly reduced. Furthermore, the hydrogels exhibited good biocompatibility as well as pH- and ion-responsive behavior, while maintaining structural stability under varying external stimuli. Notably, the swelling ratio increased in high-concentration salt solutions, making them promising for applications in controlled drug release, intelligent monitoring, and especially in seawater desalination treatment.</p>