Due to the lack of engine masking noise, gear whine has become one of the primary challenges of electric vehicles (EVs) compared with internal combustion vehicles (ICVs). Specifically, the task of evaluating and optimizing gear whine in complex, multi-scheme, and multi-condition assessment scenarios is particularly challenging. In this study, a systematic approach is developed through DOE analysis and exhaustive method validation by utilizing QI values and gear whine-related parameters. This methodology enhances evaluation accuracy and offers clear guidance for determining optimal value and tolerance combinations of gear whine-related parameters, thereby improves the gear whine performance.