Abstract: Abstract：Doubling-fed wind turbines are currently the main models of grid-connected wind turbines and Doubling-fed wind generator is an important component that affects the performance and reliability of the doubly-fed wind turbine. As generators run longer and longer on towers, generator design problems are gradually exposed. This paper mainly analyzes the design defects of high-voltage doubly-fed generators, focusing on the defects of the rotor end winding and the fixed structure of the rotor lead-out cables .Based on finite element analysis reconstruct defective structures and formulate technical renovation and maintenance plan .In order to maximize the reliability of generators, reduce wind farm operating costs and later maintenance costs.