Bone regeneration in diabetes-related defects is severely impaired by high-glucose-induced chronic inflammation, oxidative stress, and impaired angiogenesis, resulting in limited repair efficacy of conventional scaffolds in this complex microenvironment. This study constructed a 3D-printed methacrylated dextran (DexMA)/polydopamine-modified hydroxyapatite (P-HAP)/Cu₂O@MXene composite scaffold that integrates photothermal sterilization, osteogenic induction, and immunomodulatory functions. The scaffold utilizes DexMA as a framework to ensure formability and mechanical properties; P-HAP enhances the bioactivity of the inorganic phase; and the Cu₂O@MXene nanocomposite imparts photothermal response and Cu²⁺ release capabilities, enabling programmable temperature control (50 °C for sterilization and 41 °C for osteogenic induction) under near-infrared excitation and local microenvironmental regulation. In vitro and in vivo experiments demonstrated that the scaffold effectively inhibited inflammatory cytokine expression, promoted M2 macrophage polarization, and synergistically promoted angiogenesis and bone remodeling by increasing CD31 and vascular endothelial growth factor expression and enhancing runt-related transcription factor 2-mediated osteogenic activity. The proposed intelligent scaffold strategy integrates spatiotemporal responsiveness with multiple regenerative mechanisms, offering a promising approach for the repair of complex bone defects under diabetic conditions.