The invention provides a warship landing simulation method of a shipboard helicopter flight simulator. The shipboard helicopter flight simulator comprises a flight performance simulation system, an operation sampling system, a display system, a fix-degree-of-freedom moving system, an instrument system and a warship simulation system; when the relative position relationship between a helicopter and a warship deck is judged, the coordinate of an undercarriage under a helicopter system is directly transformed into a warship system, whether the helicopter undercarriage is located above the deck or not and compressed or not can be more simply and accurately judged, and the compression amount is conveniently and directly calculated. When the relative speed relationship between the helicopter and the warship deck is judged, the speed of a warship is projected to the helicopter body axis through coordinate transformation, force borne by the helicopter undercarriage and applied moment on the helicopter are directly projected to the helicopter system conveniently, and the fidelity of a warship landing process of the shipboard helicopter flight simulator is improved.