Abstract: To screen fruity flavor-producing bacteria and improve the quality of domestic cigar tobacco leaves, flavor-producing bacteria were isolated by the dilution coating method. The bacteria were screened for flavor-producing ability, aroma retention time and irritation, and identified by 16S rDNA sequence analysis combined with microscopic characteristics. The sensory evaluation scores of the machine-made cigars and the OD₆₀₀ values of the fermentation broths of the bacterial strains were used as indexes to optimize the culture conditions. The aroma components in the fermentation broth were analyzed by GC-MS, and the fermentation broth was then used to ferment domestic cigar tobacco leaves. The results showed that: 1) Twenty bacterial strains were isolated from the surface of flue-cured tobacco leaves from Brazil, Henan Province and Yunnan Province, in which M-8 strain had better flavor-producing ability and was identified as Staphylococcus equorum. The optimized culture conditions for M-8 strain were temperature at 30 ℃, pH at 7.0, and culture time at 36 h, and the optimized carbon source and inorganic salt were glucose and calcium chloride, respectively. 2) A total of 29 volatile components were identified in the fermentation broth of strain M-8. Among them, 3-methylbutyric acid, 2-methylbutyric acid, 2-methylbutanoic acid ethyl ester, benzenemethanol, ethyl benzoate and 3, 5-dihydroxy-3-methylpentanoic acid δ-lactone were revealed as the main aroma components with fruity, sweet and floral scents. 3-Methylbutyric acid and 2-methylbutanoic acid ethyl ester contributed more to the sensory quality due to their higher OAVs and ROAVs. 3) After fermentation with S. equorum, the contents of aroma components, such as 3-methylbutyric acid, 2-methylbutyric acid, 4-butylbenzoic acid 2-phenylethyl ester, 5, 6, 7, 7a-tetrahydro-4, 4, 7a-trimethyl-2(4H)-benzofuranone, megastigmatrienone and 6-ethyl-5, 6-dihydro-2H-pyrano-2-one, in Chuxue 14 cigar filler tobacco leaves were significantly increased, the fruity, honeysweet and bean aroma scents were significantly promoted, the offensive odor and irritation were reduced and the aftertaste was more pleasurable. Therefore, S. equorum derived from the fermentation could be used to improve the quality of domestic cigar tobacco leaves.