Abstract: To elucidate the effects of different rehydration water types on microbial community dynamics and quality in cigar tobacco leaves (CTLs) during fermentation, CTLs were rehydrated using either industrial running water (RW) or purified water (PW) before fermentation. The physicochemical properties, sensory quality, and amplicon sequencing of CTLs during fermentation were monitored. The results showed that total sugar, reducing sugar, starch, lignin, pectin, total polyphenols and tensile strength of tobacco leaves gradually decreased during the fermentation process, while pH and all sensory evaluation indexes showed an increasing trend. Two-way ANOVA analysis showed that rehydration water types and fermentation time had interaction effects on physicochemical properties and sensory quality of CTLs. Particularly, pH, total sugar, reducing sugar, flue gas concentration and aroma types exhibited statistically significant variations. No significant differences were observed in individual sensory quality indexes between RW and PW treatment, but PW treatment could enhance the overall quality score and reduce the types of offensive odor. Pseudomonas, Staphylococcus, Sphingomonas, Pantoea, Aspergillus and Sampaiozyma were identified as the potential key driving factors of CTLs fermentation. Total sugar, reducing sugar and pH significantly influenced microbial community abundance. Rehydration using running water increased bacterial community complexity, introduced diverse non-functional bacteria and reduced the relative abundance of functional bacteria such as Pseudomonas and Staphylococcus. These exogenous microorganisms likely established antagonistic or competitive interactions with the indigenous microbial community in CTLs. In conclusion, CTLs rehydrated with purified water demonstrated superior performance in maintaining functional microbial community abundance and enhancing fermentation quality stability.