A formidable challenge still exists nowadays in the fabrication of porous scaffolds with high mechanical performance essential for the regeneration of load-bearing bone tissues. Herein, high-pressure compression molding was utilized to structure a porous composite scaffold comprising poly(L-lactide) (PLLA), poly(lactide-co-glycolide) (PLGA), and hydroxyapatite (HA) aiming at enhancing the mechanical performance. The morphological observation indicates formation of a compact interpenetrating network structure and an optimized crystalline architecture in the high-pressure compression molded (HPCM) scaffold. The yield load and Young's modulus of the HPCM scaffold molded under the condition of 1000 MPa/180 °C/45 min climb remarkably up to 71.45 N and 6.84 MPa, respectively, which become the highest values reported to date. The HPCM scaffold possesses an interconnected porous structure with a porosity of above 80%, an appropriate degradation rate, and an enhanced cellular proliferation. The HPCM scaffold is further investigated for the reparation of rat calvarial defect. Fascinatingly, all the data of high X-ray radiopacity, considerable bone density, enhanced biomineralization, excellent biomechanics, and upregulated osteogenesis-related proteins demonstrate that the HPCM scaffold efficiently stimulates bone restoration and osseous tissue integration. The intriguing features suggest a prominent potential of our ultra-high-modulus scaffold for supporting the infiltration and reconstruction of bone in calvarial defects.