This paper discusses the application of gray model and operational research in distributing of Airport rail to landside traffic.First of all,we used GM(1,1)forecast the landside traffic volume of Beijing Capital International Airport.And,we obtained the number of passengers to airport by bus and taxi.Moreover,we applied queuing theory to analyze the distribution of airport rail to bus and taxi and gained the respective distributing rate and volume.Last,based on the Markov Chains,we forecasted the distributing trend and obtained the steady distributing rate.