Abstract: In the research of the aircraft carrier,the airflow field of deck is an important part of combat effectiveness. The main points of the current study of ship airflow field is on the resistance calculation of ship's above water part and the simulation of the pressure field and velocity field,and the study of the airfield vorticity is not fully. This research uses scattering infinitesimal areas to calculate the vorticity. Each infinitesimal area,whose vorticity is worked out,on the cross sections in key positions are used to calculate the overall vorticity and uniformity of the cross sections with the statistics method,and the overall airflow field will be simulated with the Navier-Stokes equation and the FLUENTsoftware. Finally the comprehensive assessment of the large ship will be obtained to compare the cross section's vorticity and dispersion of vorticity. A method of the performance of large ship will also be acquired.