Electrochromic materials have been applied in energy-saving buildings, intelligent displays, and other fields, recognized as one of the most promising intelligent materials for research. Liquid phase method for preparation of WO₃ electrochromic thin filmscan construct complex polychromies structures, showing great potential in modulation amplitude and short response time, especially in large area and low cost preparation. This study aims to develop a low-cost, easy-to-scale WO₃ nanocrystalline liquid phase coating process, and improve cycle stability and preparation process. WO₃ electrochromic films with high modulation amplitude, rapid response and fatigue resistance were prepared. Optimized the annealing process, WO₃ nanopowders were synthesized with low aggregation and high crystallinity, and then WO₃ nanocrystalline coating solution was prepared by ball milling dispersion. Thin film microstructure and coating solution crystallinity were optimized. The obtained thin electrochromic films of WO₃ show high tuning amplitude (82%), short response time (t_c/t_b: 8 s/4.2 s), high colouring efficiency (81.5 cm²·C^-1), and high cycling stability (> 1000 times). In this work, the crystallization and dispersion properties of WO₃ nano-powder were modified to comprehensively improve the performance of WO₃ electrochromic films prepared by nanocrystalline liquid phase coating technology. All results above demonstrate that the WO₃ electrochromic film prepared by the liquid phase method is expected to be used in the future with high color-changing performance and cycle stability.