China"s offshore wind power is in the rapid development stage, jack-up platform ship plays an important role in the construction of offshore wind farm, and its pile leg stability is directly related to the safe operation of platform ship. Based on the finite element software ABAQUS, a finite element model of pile leg of jack-up platform is established to analyze the dynamic response characteristics of the structure under combined wind and wave loads. The results show that there is no resonance risk between jack-up ship and wave; Wind load is the main factor affecting the stability of the whole structure, and the dynamic response of the structure increases with the increase of wave flow load and wind load. Extreme stress and displacement response will be generated when wind, wave and current load act on the axis of pile leg vertically. The connection between pile leg and platform should be strengthened in structural design. The research results of this paper provide a scientific basis for the design and improvement of jack-up platform ships, and have important theoretical significance and application value for ensuring the safe operation of platform ships in harsh Marine environment.