Wood is a hierarchically structural material with highly porous characteristics. However, it has not targeted on structural design in precise nanostructured control of the wood cell wall, which could extend the multiple functionalities range. Recently, emerging nanotechnologies have been explored the great potentials of wood to smart and functional materials. Wood nanotechnologies and cell wall engineering strategies are applied to tailor the nanostructure of wood through a top-down approach with additional functions, such as conductivity, magnetic property, and sensing performance. This also provides research insights about how nanotechnology and cell wall engineering could be turned into an asset for making truly smart and functional nanostructured wood products. The combination of nanotechnology and wood science is able to convert natural wood to smart and functional materials. Some examples will be highlighted for how the hierarchically structured wood/films can be better utilized. Future challenges of using wood substrates for developing advanced materials will be discussed. In the perspective of sustainable development, an outlook will be given on technological potentials of combining wood nanotechnologies and cell wall engineering.