High-entropy doping has been demonstrated to be an effective method for enhancing the electrochemical performance of NASICON cathode materials, yet the underlying mechanisms remain unclear. In this study, we employ V-based sodium superionic conductor (NASICON) cathode materials as a model system to investigate the impact of various substituting elements (Al, Cr, Fe, Ga, and In) on the local structure of the material. This strategy is proven to effectively suppress V-ion migration and, as a consequence, enhance the reversibility of multielectron reactions. By combining electrochemical analysis and spectroscopic techniques (in situ XRD, STEM, and XAFS), we investigated the changes in the composition, structural evolution, and distortion of the VO