Based on computational fluid dynamics model (CFD), the wind field distribution around the observation platform was simulated at the wind speed of 2 m·s-1, 4 m·s-1, and 6 m·s-1. The wind direction range with the least influence of platform obstacles under varied wind speed conditions was determined. It is found that the influenced range of the platform on the background wind differed due to varied wind speed conditions. The greater the wind speed, the greater the influence of the platform on the background wind. Turbulent flux under different wind directions was calculated by eddy correlation method, a quantitative analysis of influence of the platform interference on calculating air-sea flux. The results show that the air-sea flux calculated from observations under upwind is lower than that under side wind, which means the flux calculated from observations under upwind may be lower than the actual.