According to the actual measurement data and the Stokes wave theory,we study the effect of nonlinear wave loads on the offshore wind turbine foundation.When the wave characteristic parameters are determined,the velocity potential,velocity field and acceleration field function of the wave can be calculated,and the variation regularity can be analyzed.The wave characteristics of variable parameters and cycle wave loading extreme variables are predicted using BP neural network,and the probability density function of wave load extreme value distribution is fitted using Matlab.