Abstract: A fatigue-resistance topology optimization（TO）method based on augmented Lagrange function was proposed,in order to achieve a lightweight design for wind turbine main bearing seats. The quasi-static method was employed to efficiently obtain the timevarying stress. Consequently,the cumulative fatigue damage was determined by rain-flow counting. Using variable density method,the fatigue-resistance topology optimization formula was established. To address the difficulty of a large number of constraint equations imposed on unit fatigue damage,the original topology optimization problem was converted into a sequence of unconstrained optimization problems by means of augmented Lagrange function. The fatigue-resistance topology optimization function was realized by implementing the secondary development of commercial finite element software. The software has been successfully applied in the lightweight design of the main bearing seats of wind turbines,demonstrating the practicability and applicability of the proposed method.