Application of computer simulation techniques in traffic reconstruction will contribute to the sustainable development of protection of pedestrians and driver. In this paper, introducing National Automobile Accident In-Depth Investigation System Nais. The proposed database establishment could handle data while cases accumulate to a certain degree. Based on its strict workflow and thought process, take a collision accident as an example, collecting accident information, using PC-CRASH to reconstruct this accident. Evaluating consistency of simulation results and accident. Finally, in the light of this vehicle, making safe evaluation and analyzing the reason of airbag unexploded. The proposed database provides a powerful and extensible framework that is particularly well suited to analyzing big variety data in traffic accident.