On the basis of the impact of the virtual "field" for pedestrian and biased random walkers, the pedestrians' collective evacuation model and the three - dimension simulation are discussed. According to the micro - simulation model on the foundation of details of pedestrians' behavior, we studied the effect of exit width and exit position of a room on evacuation efficiency. Combined with real-time three-dimensional virtual reality software, you can achieve a dynamic three-dimensional visualization of the process of pedestrian evacuation of a room.