Objective The purpose of the current study is to explore the frequency domain characteristics of pedestrian head dynamic response in vehicle collisions and to investigate the correlation between frequency domain parameters and time domain injury criteria. Methods Finite element modelling based on a human body model was used to simulate the process of pedestrian head-to-vehicle impacts and the wavelet packet signal analysis method was employed to obtain the frequency domain response of pedestrian head in the simulations. Results The head energy in impacts at the hood area is mainly dispersed in the 0-300Hz frequency band, while the head energy in contacts at the windshield area is mainly concentrated in the 0-5Hz frequency band. The peak energy of frequency band for pedestrian head generally increases with the increase of linear and rotational speed, and the influence of rotational speed on the peak energy of frequency band is more significant when the linear speed is higher. The linear correlation R2 values between the peak energy of the head frequency band caused by the collision between the hood and windshield area and the time-domain criterion for skull injury are 0.85 and 0.61, respectively. But their correlation with the time-domain indicators for brain injury evaluation is relatively low (R2<0.5). Conclusions The frequency domain response characteristics of pedestrian heads are affected by collision speed and position. The peak energy of the frequency band can potentially characterize the risk of skull injury, but the frequency band and concentration of the peak energy of the frequency band are not related to the risk of head injury. The results of this study can provide basic reference for the evaluation of head blunt injury combined with time-frequency response.