Abstract: The mechanical performance of prestressed anchor bolts in wind turbine foundations is different from that of the forged flanges between tower tubes because of the influence of the foundation stiffness of the anchorage zone. In this study,an engineering calculation method for prestressed anchor bolts in wind turbine foundations is derived using Petersen method. Finite element models with both single and all anchor bolts are developed to investigate the spatial effect of foundation constraint stiffness. By comparing the tension forces of anchor bolts in the two numerical models,it is concluded that the spatial effect of foundation constraint stiffness can be disregarded. The accuracy of the engineering calculation method is validated by comparison with the numerical results of the finite element model with all anchor bolts.