Objective To study the relationship between the severity of pedestrian head injury and the impact speeds, the vehicle types and the impact positions in pedestrian-vehicle accidents by computer simulation based on the real accident video. Methods A pedestrian-traffic accident with the video was reconstructed by the MADYMO multi-body dynamics software to obtain the initial and boundary conditions. Experimental impact simulations were conducted on different vehicles (car, SUV and minibus) and pedestrian impact positions (front, side and back structure) by different speeds (20, 30, 40, 50 and 60 km/h) to analyze head injuries, and the simulation results were validated by two real pedestrian-vehicle accidents. Results Not only the impact speed and the front structure influenced the pedestrian head injury severity, but also the impact position of pedestrian was an important factor. At the collision speed ≤30 km/h, the pedestrian head injury caused by the contact with the ground could be possibly more serious than the contact with the vehicle; while at the collision speed≥40 km/h, the pedestrian head injury was mainly caused by the contact with the vehicle. Conclusions The pedestrian traffic accident can be accurately reconstructed by using the real accident video to analyze the pedestrian head dynamic response. The severity of pedestrian head injuries can be effectively reduced by speed limitations on different types of vehicles at pedestrian traffic accident black-spots.