Abstract: In order to study the regulation of dynamics response for the motorcycle's rider and the car after the collision, based on a real case in the National Vehicle Accident Investigation System (NAIS), a 90°motorcycle and the car front collision model was built by means of the PC-Crash software. On this basis, simulation tests were carried out to study the impact of rider sitting posture and the speed of the car on rider's head injury. The results show that when the speed of the car is constant, the HIC value of the rider increases with the increase of the rider's sitting angle, that the point of time at which the collision occurs between the rider's head and the car comes earlier as the rider's sitting angle increases, that when the motorcycle speed is constant, this is a positive correlation between the HIC value of the rider increases and the rider's sitting angle, and that the point of time at which the collision occurs between the rider's head and the car's contact collision moment comes earlier as the rider's sitting angle increases.

Key words: rider, head injury criterion(HIC), rider's sitting angle, accident reconstruction, PC-Crash