Abstract: In order to explore more efficient and scientific base liquor quality grade evaluation methods,this study took Luzhou-flavor base liquor as the research object. Firstly,the sensory grading of the base liquor was carried out and the 43 volatile flavor components were qualitatively and quantitatively analyzed by gas chromatography-quadrupole flight time mass spectrometry (GC-QTOF MS). Then the precision,repeatability and stability of the method were investigated and the results were analyzed by factor analysis and regression analysis. The results showed that the RSD ≤ 2.98% of the relative retention time and content of 43 volatile flavor components in the mixed base liquor samples with the same volume of three quality grades and the method had good precision,repeatability and stability within 60 h. Ten Luzhou-flavor base liquors could be divided into three grades by sensory evaluation,and the 23 volatile flavor components were retained by factor analysis to eliminate the variables corresponding to the largest eigenvector in the principal components with the eigenvalue less than 1,which could also be used to effectively classify the 3 grades of base liquor. Then,a mathematical evaluation model of Luzhou-flavor base liquor grade was established by linear regression analysis with the comprehensive score F of principal components as the independent variable and the comprehensive score Y of sensory evaluation as the dependent variable. This model was Y=8.2329F+86.4 (R²=0.9801),which could preliminarily evaluate the three grades of Luzhou-flavor base liquor samples with the accuracy 85.71%.