The layer-by-layer（LbL） assembly method comes to the fore in many methods of preparation of nanocellulose-based functional composites for it possesses many advantages such as simple principle, easy operation and adjustable structure. Herein, the principle and existing approaches of the LbL assembly technique were presented. According to the role that nanocellulose plays in functional nanocomposites, three parts were then divided to elaborate preparation technics, structural and functional characteristics. Future research and development of the LbL assembled nanocellulose-based functional composites were proposed.