The high frequency noise of Electric Vehicle Powertrain greatly impacts the vehicle’s sound quality. Therefore, vibration and noise tests of Electric Vehicle Powertrain are conducted. Thereafter, objective evaluation of the collected noise signals is done for sound quality assessment. In the subjective evaluation part, factor analysis of objective parameters is introduced. Sound quality feature factors are extracted. A method based on descending order arrangement and odd even grouping is put forward. The differences in sound quality features among groups, occurring after grouping by the adaptive grouping paired comparison method, are reduced. Thus, the accuracy of subjective evaluation results is improved. Finally, the subjective annoyance degree score of Electric Vehicle Powertrain under Steady-speed conditions is obtained. This study helps achieve efficient and accurate prediction of the sound quality of Electric Vehicle Powertrain.