In order to study the influence of ship tail structure on the airwake, the simple frigate shape SFS1 has been chosen for this study and the numerical simulation of ship airwakes hasbeen performed. The ANSYS FLUENT standard turbulence model is used on the structured grids generated byANSYS ICEM. The influences of the closing/opening state of the hangar, the hangar height and the flight deck length were simulated. The ship airwakes in different conditions were compared by analysing the physical parameters such as the velocity and pressure. It is shown that: the flow field environment will become better when the hangar height becomes lower and the flight deck beomes longer; the airwake becomes worse when the door is ajar than that when the door is closed or open; while neither airwake is superior when the door of hangar is closed or open completely. The present work will provide theory and data support for the modification of ship in service and the improvement of ship in construction,which will improve the ship airwake for shipboard aircrafts, and the capability to command and control the launch and recovery of shipboard aircraft.