Objective This study aimed to breed and analyze the aroma characteristics analysis of functional Bacillus subtilis strains derived from high-temperature Daqu to enhance the sauce-flavor and quality stability of sauce-flavor liquor.Methods A combination of solid-state and liquid-state fermentation along with electronic sensory analysis was employed to identify strains with enriched sauce flavor. The solid-state fermentation conditions for aroma production were optimized, and the characteristic aroma compounds were identified using gas chromatography.Results A strain of B. subtilis, Bac14, with sauce-flavor-producing advantages was obtained, and the optimal condition for its sauce-flavor-producing flavor is the temperature gradient of 37 ℃→45 ℃→50 ℃→55 ℃, the vaccination ratio is 10%, and the water content is 50%. Under the control of these conditions, the strain has significant aroma production, and related flavor substances such as 3-hydroxy-2-butanone, 2,3,5-trimethylpyrazine, 2,3,5,6-tetramethylpyrazine, and furfural have significantly increased.Conclusion A high-temperature Daqu-derived B. subtilis strain with excellent sauce-flavor-producing properties was obtained, and its optimal aroma-producing conditions were established. This study provides a foundationfor developing enhanced Daqu and improving the quality and stability of sauce-flavor liquor.