Abstract: In order to reveal the influence mechanism of sea-air exchange on horizontal wind speed in the whole process of typhoon transit,a real-time coupling simulation method of atmospheric WRF model,wave SWAN model and marine FVCOM model is established based on the secondary development of MCT coupling platform. At the same time,it is compared with the prediction results of single mesoscale WRF model. Through correlation analysis,the main environmental factors affecting the horizontal wind speed of typhoon by sea-air exchange are determined,and then the mechanism of sea-air exchange is revealed. Finally,the comprehensive environmental factor’s influence coefficient of sea-air exchange at different stages of typhoon is studied by principal component analysis.The results show that the main environmental factors in the influence of sea-air exchange on Typhoon horizontal wind speed are as follows:vertical shear,friction velocity,sea surface temperature,latent heat flux and 850 h Pa vertical vorticity. Considering the sea-air exchange,the influence of comprehensive environmental factors on horizontal wind speed shows a negative feedback trend. The values of the sea-air exchange index of the environment on wind speed in the whole process of typhoon transit are 0.206（acceleration period）,-0.718（strong wind period）and-0.750（landing period）.