Abstract: The causes of formation of sudden sodium layer are not confirmed. The main viewpoints include effects of meteor ablation, dust release and atmosphere dynamics. To research into the influence of atmosphere dynamics to formation of sudden sodium layer, we simulate sudden sodium layer by applying the continuity equations for both atomic sodium and the background neutral atmosphere. As far as vertical winds are concerned, we adopt the model of a sine travelling wave which approaches the real one. The results reflect the process of sudden sodium layer's formation and development. The instant of sudden sodium layer's formation is from 5-minute to 15-minute and sudden sodium layer can last to 30-minute. The altitude of sudden sodium layer is from 90-kilometer to 100-kilometer. The width of sudden sodium layer is from 0.5 kilometers to 2 kilometers. All these are in agreement with the data obtained. And this paper also researches the tendency of sudden sodium layer's development when the parameters of gravity waves alter, including vertical wave length, wave period, velocity of the vertical winds and half-width of normal sodium layer. In all these factors, velocity of the vertical winds and half-width of normal sodium layer influence the formation of sudden sodium layer greatly. To validate the reliability of the simulation, this paper provides two cases of observation. Comparing the result of the simulation with the observation, we find that they are close to each other.