Mechanical metamaterials designed using triply periodic minimal surfaces (TPMS) are notable for their mathematically defined topologies that yield specific and impressive mechanical properties. Recently, the use of fiber‐reinforced composite material structures in fields such as mechanical engineering and aerospace technology has significantly increased. However, the performance of fiber‐reinforced mechanical metamaterials based on TPMS has not yet been reported. Therefore, herein, the changes in the vibration isolation and energy absorption performance of TPMS mechanical metamaterials after fiber reinforcement are investigated. Thermoplastic polyurethane is used as the matrix material for the structure and T300 carbon fibers as the reinforcing phase material. First, the equivalent material parameters of TPMS mechanical metamaterials reinforced with carbon fibers using theoretical and finite element methods are obtained. Second, the quasi‐static compression characteristics of mechanical metamaterials are analyzed. Finally, the band structure and energy absorption properties of the TPMS structures are examined. The numerical simulation results show that fiber reinforcement can significantly enhance the stiffness and impact resistance of TPMS mechanical metamaterials. The study provides theoretical guidance for the design and manufacture of mechanical metamaterials and their applications in future aircraft.