The numerical analysis method of HAWT structure dynamic response was investigated under stochastic wind loading. And the estimation method of equivalent fatigue life based on the Palmgren Miner linear damage rule was set up. Using the finite element numerical analysis method, the fatigue load spectrum of the blade such as the displacements, velocities, accelerations and stress were resolved. Counting the statistics cycle parameters by rainflow method, the work stress level was transformed into symmetrical cycle fatigue load spectrum. Through FE-SAFE fatigue analysis module, the fatigue properties of the finite element model were analyzed. As an example, the fatigue load and fatigue property of a 1.5MW wind turbine blade was calculated using the Matlab simulation program and ANSYS software.