Yellow water is a unique by-product of Luzhou-flavor liquor fermentation, and the yellow water parameters reflect the fermentation quality to some extent. Based on the key parameters of acidity, reducing sugar and alcohol content, the cloud model and improved D-S（Dempster-Shafer） evidence theory are used to realize the quantitative assessment of the liquor fermentation quality. The membership cloud model is established based on the key parameters of yellow water. The membership cloud model is established based on the key parameters of yellow water, and the cloud model is used to determine the membership of the samples in each fermentation quality determination interval. At the same time, the calculation method of the conflict coefficient of D-S evidence theory is improved to make the information fusion results more representative. A comprehensive evaluation method of fermentation quality of Luzhou-flavor liquor is proposed to reduce the subjectivity of manual discrimination.