Abstract Living cells and organisms are composed of numerous biomolecules and control their concentrations and spatial distribution in a spatiotemporal manner to exhibit intricate biological functions. Inspired by the extracellular matrix, synthetic multi-network hydrogels have attracted attention due to their remarkable properties like extremely high toughness. This account summarizes our research progress on one emerging class of the multi-network hydrogels, supramolecular–polymer composite hydrogel. Composite hydrogels can rationally integrate stimulus response of supramolecular gels and stiffness of polymer gels. Super-resolution microscopy visualizes four types of network patterns at the µm scale: an orthogonal and three interactive networks, which may influence the viscoelastic properties of composite hydrogels. We found a kind of composite hydrogel that shows autonomous network remodeling, enabling fracture-induced 3D gel patterning. Furthermore, we demonstrated that supramolecular–polymer composite hydrogels are applicable as a matrix for controlled release of protein biopharmaceuticals in response to antibodies through incorporation of functional molecules such as enzymes and their inhibitors. Supramolecular–polymer composite hydrogels hold promise as the next-generation smart and responsive soft materials for biomedical applications, including tissue engineering and regenerative medicine.