Abstract: 【Objective】 This study aimed to investigate the effects of mechanical regulation and gas regulation on microbial community structure of aged tobacco leaves and dominant microbial communities in moldy tobacco leaves， providing a technical basis for mold prevention， quality improvement， and efficiency enhancement.【Method】 Taking the Yunyan 87 strips （C3F） from Yunnan in 2022 and stored at Wuhan Ledao Logistics Co.， Ltd. as the research objects， two treatments were set： mechanical regulation （J） and gas regulation （Q）. Bacterial （16S rDNA V5-V7 regions） and fungal （ITS1 region） diversity were analyzed using high-throughput sequencing， while predominant mold strains were screened through mold induction， isolation， culture， and molecular identification.【Result】 No significant differences were observed in the alpha diversity indexes （ACE， Chao1， Shannon， Simpson’s indexes） of bacteria or fungi between the two treatments （P>0.05）. However， non-metric multidimensional scaling analysis revealed significant separation in microbial community structure between the two treatments. Except for sample J2， Sphingomonas was the dominant bacterial genus across all samples with its relative abundance of 68.98%-86.86%； Pantoea was the dominant bacterial genus in sample J2 （relative abundance of 22.78%）. The dominant fungal genera were consistently Aspergillus， Alternaria， Cladosporium， and Filobasidium across samples. Linear discriminant analysis effect size （LEfSe） identified 12 significantly different bacterial genera， all of which were enriched in the aged tobacco leaves under mechanical regulation （P<0.05，the same below） and nine significantly different fungal genera were identified （seven enriched in the aged tobacco leaves under mechanical regulation， two enriched in the aged tobacco leaves under gas regulation）. After mold induction， the dominant microbial communities in moldy tobacco leaves under mechanical regulation were Aspergillus flavus， Penicillium citrinum， and Psathyrella gracilis； the dominant microbial communities in moldy tobacco leaves under gas regulation were Fusarium proliferatum， Aspergillus niger， and Byssochlamys spectabilis.【Conclusion】 Although mechanical regulation and gas regulation do not significantly alter the overall diversity level of microbial community in aged tobacco leaves， they significantly reshape the structure composition and differential species distribution of microbial community， thereby determining distinct dominant mold communities in moldy tobacco leaves.