Fluent and ANSYS Workbench platfrom are applicated to make a research on the time course of jack-up drilling platform under extreme wave load. Track free surface with UDF macro and VOF method. Establish numerical wave flume with the function of wave generation and wave absorbing to simulate limit value linear wave and third order Stokes wave. Flow field physical model of jack-up drilling platfrom and trussed legs are established to study the time course of wave load under wave impact. Analyze wave pressure and speed distribution of the field around trussed legs and platform and calculate the stress distribution of platform structure under wave load. The calculating results of wave load will provide a basis for evaluating the influence of wave load to drilling platfrom and designing drilling platfrom rationally.