The invention relates to reappear three dimensional deformation of a vehicle body in a collision accident, including the steps: building an accident occurrence environment and finite element models for the related vehicles in the accident; verifying the reliability of the finite element models; selecting vehicle body key points adaptive to head-on collision and oblique collision and processing the holes in a numeric model; using three-coordinate measurer to physically measure the fixed key point positions; to a finite element model for the whole vehicle, adopting key point deforming measuring method; by multiple iterative optimization calculation, if finding the numeric simulated result of the deformed key points is consistent with the actual collision measured result at a certain speed and collision angle, determining the accurate automobile speed and collision angle at the occurring time of the accident. The invention can recover the accident on the condition that the trace of the wheels and other field information are destroyed or not clear, and has better objectivity because of making three-dimensional measurement on the measured points of the main energy absorbing components.