Based on social force model which is combined statistics and analysis of crowd motion characters and body motion parameters in the field of transportation and biodynamic, vibration comfort of long-span corridor under stochastic crowd load is studied and stochastic crowd motion is simulated.The critical parameters such as pace and landing position are obtained in different densities, the stochastic crowd model is built and the peak acceleration is calculated.The study shows, peak acceleration is closely related to the pacing frequency, and pedestrian velocity becomes large along with increase of pedestrian density while the acceleration response of structure increased initially and then decreased. By the relationship curve of structure peak acceleration and pedestrian density the pedestrian density interval in which the structure suffering vibration serviceability problems can be found.