In order to research the influence of road condition on running safety in atrocious weather, vehicle dynamics model, road model and vehicle-road coupling model were set up by using multi-body dynamics software ADAMS/Car. By changing road friction coefficient, road conditions in sunny day, rain, snow and freezing weather were simulated. Two virtual tests of single lane change and step steering were carried out, and the response outputs of lateral displacement, course angle and lateral force of tires were obtained. Computation result indicates that when road friction coefficient in snowy weather is 0.28, vehicle speed is 50 km·h-1 in the single shift line simulation, the lateral displacement of vehicle will reach 4.50 m, the vehicle will overrun runways and have a risk of collision. When vehicle speed is 40 km·h-1 in the step steering simulation, vehicle will go haywire.