Ship air wake flow field has complex structures, which seriously affects the aerodynamic environment of rotor and the landing safety of helicopter. This paper proposes the numerical simulation method of helicopter’?s dynamic landing based on computational fluid dynamics (CFD), and studies the changes of helicopter’?s aerodynamic load in the landing process. The N-S equation is used as the governing equation. The model is selected as the turbulence model to improve the simulation accuracy of the vortex field and the rotor adopts the momentum source method. Based on the above method, the characteristics of the coupled flow field and the aerodynamic load changes during the helicopter’s landing are analyzed. The results show that when the helicopter enters the field from ship?’?s one side, the rotor will have strong eddy interference with deck-edge vortices and large recirculation zone, which leads to a significant reduction of thrust. An additional roll moment can be easily produced because of the shipboard effect, which affects the stability of the helicopter. Under the combined effect of the above interference, the rotor thrust is reduced at first and then increases. The aerodynamic load will fluctuate sharply when the helicopter approaches the deck, which will increase the risk of landing for shipboard helicopter.