This study investigates the development of a high-performance sodium halide solid electrolyte, Na1-xZrxLa1-xCl4, for all-solid-state sodium-ion batteries (ASSBs). The electrolyte is designed to exhibit high ionic conductivity, good compressibility, and oxidative stability. Through a combination of solid-state reaction and mechanochemical methods, the electrolyte is synthesized with a hexagonal structure (P63/m) and high ionic conductivity of 2.9 × 10^-4 S cm^-1 at 30°C. The ionic conductivity is attributed to the one-dimensional diffusion channels formed by Na+ ions, which are influenced by the size of Na+ channels and the mixing of Na+/La3+ ions. The electrolyte demonstrates excellent electrochemical performance in ASSBs, achieving an initial capacity of 114 mA h g^-1 and 88% retention after 70 cycles at 0.3 C, and maintaining a capacity of 94 mA h g^-1 at 1 C. The study also highlights the importance of Zr4+ doping in expanding the Na+ diffusion path, enhancing the ionic conductivity and electrochemical stability of the electrolyte.This study investigates the development of a high-performance sodium halide solid electrolyte, Na1-xZrxLa1-xCl4, for all-solid-state sodium-ion batteries (ASSBs). The electrolyte is designed to exhibit high ionic conductivity, good compressibility, and oxidative stability. Through a combination of solid-state reaction and mechanochemical methods, the electrolyte is synthesized with a hexagonal structure (P63/m) and high ionic conductivity of 2.9 × 10^-4 S cm^-1 at 30°C. The ionic conductivity is attributed to the one-dimensional diffusion channels formed by Na+ ions, which are influenced by the size of Na+ channels and the mixing of Na+/La3+ ions. The electrolyte demonstrates excellent electrochemical performance in ASSBs, achieving an initial capacity of 114 mA h g^-1 and 88% retention after 70 cycles at 0.3 C, and maintaining a capacity of 94 mA h g^-1 at 1 C. The study also highlights the importance of Zr4+ doping in expanding the Na+ diffusion path, enhancing the ionic conductivity and electrochemical stability of the electrolyte.