Abstract: To minimize aroma loss of peppermint powders in cigarette filter rods, the aroma retention capacity was promoted by adding propylene glycol (PG) to peppermint powder. The effect of PG addition rate on the mass fractions of volatile aroma components in peppermint powders was analyzed by GC-MS. The optimal PG addition rate was determined, and the distribution characteristics of moisture in different binding states with peppermint powders were measured by low-field nuclear magnetic resonance (LF-NMR). The aroma retention mechanism of peppermint powders was investigated, and the peppermint powders with added PG were used to flavor cigarette filter rods. The results showed that: 1) The number of volatile aroma components in peppermint powders without PG decreased to 22 after storage for 90 days, and the total amount of volatile aroma components remained 40.94%. When the addition rate of PG was 2%, the peppermint powders had the strongest aroma retention capacity, the total amount of volatile aroma components remained 72.69% after storage for 90 days, the retention amount of volatile aroma components was increased by 31.75% by adding PG. 2) The results of LF-NMR analysis showed that the addition of PG significantly increased the moisture adsorption ability of peppermint powder. At 2% PG addition, the mass fraction of strongly bound water in peppermint powders was the highest. Correlation analysis results showed that the residual amount of volatile components in peppermint powders was significantly positively correlated with the relative peak area of strongly bound water. The higher the proportion of highly bound water in peppermint powder, the higher the amount of residual volatiles in peppermint powder. 3) The peppermint powders containing PG significantly enhanced the menthol flavor of cigarette smoke and increased the moisturizing sensation to some extent.