With today’s rapid development of science and technology, mechanical design calls for more advanced methodologies. The Creative Mechanical Design Methodology established by Yan  is one of the most effective ways to form new mechanisms according to existing ones based on certain requirements. However, few research of this method applied on transmission mechanism exists, especially gear trains with large rated power and transmission ratio. This paper introduces how the Creative Mechanical Design Methodology is applied in the design of the accelerator (gear box) with an output power of 1.25 MW in wind power generator. In the process, feasible schemes are obtained following the steps of Creative Mechanical Designing, and an evaluation based on practical manufacturing, assembly and application situations is conducted to obtain the best mechanism among all these schemes.