Abstract: The event of “Tesla brake failure” has sparked heated discussions in the society. In this paper, based on Ackerman steering technology and vehicle motion equations, a model is built to restore the driving state and the track before the accident according to Tesla's published data. The result is consistent with the qualitative description of the accident given by the owner. So, it can be judged that the data provided by Tesla is basically credible. This paper also discusses the three questions raised by netizens and car owners. It is proved that the braking system works normally and the possibility of overspeed driving exists.