In wind power generators, the taper angles of the inner and outer rings of the shrink disk have a great influence on the friction, but there is a lack of relevant theoretical analysis at present. Through the finite element simulation, the stress distribution, deformation range, and stress change of the inner and outer rings after the interference fit of the shrink disk are theoretically analyzed. Line charts are plotted to compare the simulation data with the theoretical calculation data. The results show that the optimal angle of the inner and outer ring cones of the wind power generator shrink disk is about 3°. The closer the angle value is to 3°, the smaller the error between the theoretically calculated interference value and the simulated interference value. In general, from the outside to the inside, the contact pressure values of the three contact surfaces of the shrink disk gradually decrease and the corresponding contact surface interference values gradually decrease. On the contact surface between the outer ring and the inner ring, the linearity of the relationship between the interference value and the angle change is the highest, and the ratio of the interference to the angle value is about 1.38.