Abstract 2D WO 3 nanomaterials have shown specific morphology, unique optical and electronic properties due to their decreasing dimension. Therefore, the preparation of 2D WO 3 nanomaterials becomes extremely important. Hydrothermal and solvothermal methods are the frequently applied methods, which can realize a large amount of productions. Other preparation methods, such as cold plasma, exfoliation, and the solid‐liquid phase arc discharge (SLPAD) route, have also shown various improvements in reducing the thickness, size control or in a simple and easy fabrication with use of fewer chemicals. When used as supporting materials, 2D WO 3 nanolamella significantly promote the dispersion of noble metals, improve the metal‐support interaction and increase the electron density of Pt. Besides, the 2D nanostructure can increase the charge‐carrier transfer rate, decrease the recombination of photogenerated electrons and holes, alter their photoabsorption properties and lead to higher specific surface area. These advantages effectively promote their optical properties and photocatalytic activity.