Macrophages are a predominant immune cell population that drive inflammatory responses and exhibit transitions in phenotype and function during tissue remodeling in disease and repair. Thus， engineering an immunomodulatory biomaterial has significant implications for resolving inflammation. Here， a biomimetic and photoresponsive hyaluronan (HA) hydrogel nanocomposite with tunable 3D extracellular matrix (ECM) adhesion sites for dynamic macrophage immunomodulation is engineered. Photodegradative alkoxylphenacyl-based polycarbonate (APP) nanocomposites are exploited to permit user-controlled Arg-Gly-Asp (RGD) adhesive peptide release and conjugation to a HA-based ECM for real-time integrin activation of macrophages encapsulated in 3D HA-APP nanocomposite hydrogels. It is demonstrated that photocontrolled 3D ECM-RGD peptide conjugation can activate αvβ3 integrin of macrophages， and periodic αvβ3 integrin activation can enhance anti-inflammatory M2 macrophage polarization. Altogether， an emerging use of biomimetic， photoresponsive， and bioactive HA-APP nanocomposite hydrogel is highlighted to command 3D cell-ECM interactions for modulating macrophage polarization， which may shed light on cell-ECM interactions in innate immunity and inspire new biomaterial-based immunomodulatory therapies.