With the increasing demand of users for the acoustical comfort of commercial vehicles, the sound quality has become one of the important indicators of comfort evaluation. The research focuses on the objective evaluation method of the subjective perception of the sound quality in commercial vehicle. The interior noises of commercial vehicle with an inline six diesel engine are measured. The five psychoacoustic parameters (loudness, roughness, sharpness, fluctuation strength, tonality and articulation index) are applied to the evaluation and analysis of the interior noises of the commercial vehicle. Using psychoacoustic parameters to evaluate the noises in commercial vehicle, it is of great significance for the analysis and control of the noises in commercial vehicle. The research results provide a theoretical basis for guiding the sound quality design and development of commercial vehicles.