Diabetes-related bone defects are severely inhibited by high-glucose-induced chronic inflammation, oxidative stress, and angiogenesis impairment, resulting in limited repair efficacy of conventional scaffolds in this complex microenvironment. This study constructed a 3D-printed DexMA/P-HAP/Cu₂O@MXene composite scaffold that integrates photothermal sterilization, osteogenic induction, and immunomodulatory functions. The scaffold utilizes methacrylated dextran (DexMA) as a framework to ensure formability and mechanical properties; apatite modified with dopamine (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 scavenged ROS, inhibited inflammatory cytokine expression, promoted M2 macrophage polarization, and synergistically promoted angiogenesis and bone remodeling by activating CD31/VEGF and Runx2 signaling pathways. This study proposed an intelligent scaffold strategy with spatial-temporal response characteristics and multi-dimensional mechanism integration capabilities, providing a new solution for the efficient regenerative repair of complex bone defects in diabetes.