A new inflow turbulence generator called discretizing and synthesizing random flow generation was applied to simulate the actual boundary conditions of turbulent flow field. A new oneequation dynamic subgrid scale (SGS) model was adopted for the large eddy simulations. The wind loads on the roof of Changsha Airport Extension Building with five wind directions were calculated on the basis of the paralleled technology of Fluent6.3 soft platform under the linux system. The distribution characteristics of the surface wind pressure on the roof and the most unfavorable wind direction were determined by analyzing the mean and fluctuating pressure coefficient contours. The results are valuable for the windresistant design of Changsha Airport Extension Building and provide useful information for the numerical simulation of wind loads of other similar structures. The results show that the response trends are the same and the response is close, though different methods were used to simulate water body and different analysis methods were employed.