On the basis of the triply periodic minimal surfaces (TPMS), some gyroid unit cell models with different relative volume percentages and the corresponding topology models were designed. The mechanical responses under different impact velocity were calculated through finite element simulation software. In addition, the stress distribution, force-distance curves, load-bearing capacity and energy absorption efficiency were analyzed and discussed. The numerical simulation results demonstrate that the TPMS porous structure had excellent energy absorption properties. The increase of relative volume and impact velocity could improve energy absorption capacity and efficiency. And under the same conditions, the energy absorption efficiency of topology model was superior to that of the corresponding unit cell. Meanwhile, it was not prone to produce stress concentration because of its uniform stress distribution. With the increase of the relative volume, the load-bearing capacity of the structure was improved obviously. The structure showed certain strain rate sensitivity, and the collapse force and platform force of the structure were significantly improved under high strain rate. The research results provide relevant basis for the optimization design of engineering products.