The invention of automobiles has brought great progress and convenience to mankind. However, There are enormous personnel casualties and economic loss arising from traffic accidents every year. In this paper, CT (computed tomography) and MRI (magnetic resonance imaging) image of the human skeleton and internal organs were used to construct the three-dimensional human body finite element biomechanical model. The mechanical properties of the biological tissues in this model were based on test data found in the literature. The model was validated against cadaver responses to frontal and side impact. The predicted model response and injuries reasonably agreed with the experimental data. Simulation study on the collision between steering wheel and chest was performed, and the biomechanical response and the deformation pattern of the human body was obtained, from which the rib fracture and visceral injury mechanism can be reconstructed. The predicted model response reasonably agreed with that the thoracic injury in real-world crashes, and the model can further be used to evaluate thoracic injury in real-world crashes.