Repairing critical-sized, load-bearing bone defects remains a formidable clinical challenge, primarily due to the mechanical fragility of traditional bioceramics. This study systematically compared the bone regenerative efficacy of surface-microstructured 3D-printed porous titanium (3D-SMPT) and biphasic calcium phosphate (RBCP) ceramics. In vitro evaluations demonstrated that a biomimetic coating effectively overcame titanium's bio-inertness, endowing 3D-SMPT with excellent biocompatibility and osteoinductivity comparable to RBCP. In vivo cross-species assessments revealed significant biomechanical differences: in a low-load rabbit ulnar model, both scaffolds exhibited equivalent osteogenesis. However, in a true weight-bearing beagle femoral model, RBCP suffered severe structural collapse due to inherent brittleness. In stark contrast, leveraging its cortical bone-matched compressive strength (83.14 MPa, approximately 10-fold higher than that of RBCP at 7.68 MPa) and interconnected porosity, 3D-SMPT perfectly maintained long-term mechanical stability, effectively mitigating stress shielding to facilitate massive mature bone ingrowth and robust osseointegration. In conclusion, 3D-SMPT achieves a perfect unification of bioactivity and load-bearing stability, overcoming the fatal fragility of traditional ceramics to provide a highly promising clinical alternative for massive load-bearing bone defect repair.