In order to explore the role of mud used to seal pits in the production process of Maotai-flavor Baijiu, the liquor-making experiments were carried out by using pit mud and not using pit mud, respectively, in the cellar fermentation process of Maotai-flavor Baijiu. The results showed that the temperature change trend, water content, starch content, acidity, reducing sugar content, production yield of the base liquor distilled from the top of fermented grains and total base liquor of the cellar were very close in different cellar sealing methods ( & quot;no mud used to seal pits/with mud used to seal pits & quot;). The base liquor produced by & quot;no mud used to seal pits & quot; method scored higher in body cleanliness than that produced by & quot;with mud used to seal pits & quot; method, but lower in sauce flavor and liquor body alcohol thickness, and similar in aftertaste and Qu flavor. However, the quality of the base liquor distilled by the two methods was qualified. Using PLS-DA model, 10 flavor compounds were identified as the key factors of quality difference. In conclusion, Whether or not to use cellar mud has little effect on fermentation process, physicochemical indexes of fermented grains and basic liquor yield in Maotai-flavor Baijiu production process, but it plays an important role in the style and quality of base liquor. Finally, according to the actual technical requirements of Maotai-flavor Baijiu enterprises, this paper puts forward some suggestions on the quality management of mud used to seal pits.