Cellulose nanocrystals, the most abundant crystalline polysaccharide nanomaterials on Earth, has been widely used for the reinforcement of polymeric materials owing to their high elastic modulus, low density, high aspect ratio, biocompatibility, and biodegradability. Herein, we present our recent works in the controllable arrangement of cellulose nanocrystals in hydrogel networks, including isotropic structure, highly oriented structure, helical structure, and gradient structure. The nanotechnology for the arrangement of cellulose nanocrystals, the design of cross-linked networks, and the potential applications of nanocomposite hydrogels are introduced and discussed. Our work provides a new strategy for the construction of soft and smart devices from bio-sourced resources.