The dynamic responses of the cutterhead driving system (CDS) of the tunneling boring machine with impact loads are investigated according to its typical structure in this paper. First, finite element model of CDS is proposed based on linear mesh stiffness hypothesis, in which the rotating components are introduced as beam elements with the same mass and stiffness characteristics, and the effects of cutterhead-rock stiffness and carrier stiffness of CDS are also taken into account. Then, the natural characteristics of the CDS and the corresponding energy distribution for the components are investigated using this model. Finally, numerical simulations are carried out to determine the dynamic responses under two different typical impacts, by means of transient trajectories in time-domain and amplitude-frequency spectra in frequency domain, respectively. With the dynamic behaviors analysis, the response frequency of the CDS and the corresponding components with the maximum load is shown at the end. This modeling approach should provide a new idea for the CDS dynamic designing.