This tudy aims to systematically compare the mechanical properties of authentic human skull and polyetheretherketone (PEEK) cranial repair material, and to evaluate the feasibility and superiority of PEEK as a skull substitute. Based on the anatomical structure of the authentic human skull, a three?layer composite geometric model of a skull?like structure was constructed using SolidWorks and imported into the ABAQUS finite element analysis software. The authentic skull (cortical bone parameters) and PEEK (medical?grade parameters) were assigned corresponding material constitutions, damage criteria, and evolution models. By setting a dynamic explicit step, surface?to?surface contact, and an initial impact velocity (4?m/s), the dynamic impact process of the skull against a rigid wall was simulated. The results show that the elastic modulus of PEEK (4800?MPa) is lower than that of the authentic skull (17100?MPa) and closer to that of human skull tissue, effectively avoiding stress shielding. The Johnson?Cook plasticity model together with the ductile damage model appropriately describes large deformation and strain?rate effects. Comparison of stress distribution, deformation patterns, and damage modes confirms that PEEK exhibits significant advantages in impact resistance, mechanical compatibility, and structural stability. This study provides systematic biomechanical data support for the optimized design, precise clinical application, and standardized promotion of PEEK cranial implants.