Abstract: In order to improve the stability of wind power speeder gear operation, this study proposed an optimized gear modification scheme combining lead and profile modifications, based on simulation analysis. An improved second generation genetic algorithm was employed to optimize the combination of gear parameters. The results showed that, after applying the second generation genetic algorithm, the transmission errors of the first-stage and second-stage planetary gears and the third-stage pinion were reduced by 75.21%, 54.17%, and 64.09%, respectively, compared to the unmodified state. Compared with traditional formula-based modifications, the reductions were 45.75%, 32.92%, and 42.86%, respectively. Additionally, the maximum vibration acceleration of the third-stage pinion bearing was reduced by 24.96% and 3.19% compared to the formula-modified and unmodified states, respectively. These findings fully validate the effectiveness and feasibility of the proposed optimization scheme in reducing transmission error and vibration.