Objective To construct a three-dimensional (3D) dynamic head-neck finite element model which accords with the anatomical structure, and study its dynamic responses under the external force. Methods By using the neck CT images of a Chinese adult male volunteer and obtaining the 3D cervical point cloud data, the finite element model of cervical spine was established using ICEM-CFD and HyperMesh software. This model, including vertebrae, intervertebral discs, facet joints, ligaments and cartilage tissues, and combining with the established and verified head finite element model, was assembled as human head-neck finite element model with detailed anatomical structures. Results The model was validated by data of head-neck axial impact experiments reported in previously published literature. The simulation results showed that the neck deformation, head acceleration, head force and injury positions were preferably consistent with the experimental data. Conclusions The established 3D dynamic finite element model can be used to study head-neck dynamic responses and damage mechanism in the fields of traffic safety and impact injuries.