Abstract: In order to study the influence of different proportion of stalks on harmful components in cigarette, the influence of 10 gradient proportion of stalks on the release amount and harmfulness evaluation index of 7 harmful components such as phenol in mainstream smoke is designed according to the principle of only changing the proportion of stalks and fixing other parameters. The results showed that: in the test range, there is a certain negative correlation between the proportion of rhizome and the release amount and H value of 7 hazardous components in the mainstream flue gas, and the decrease of phenol, ammonia, HCN and other indexes was more obvious. The effect of NNK reduction is not obvious. The phonel release, ammonia release and H value release of mainstream cigarette smoke decrease by 10.6%, 8.8% and 4.4%, when the content of stalk silk increased by 10%. When the proportion of terrier silk is 25%, the decline trend of H value index tended to bi gentle. From the perspective of coke reduction and damage reduction, the proportion of terrier silk is not more than 25%. In the experimental design of coke reduction and harm reduction, the regression equations can be used as the prediction model of the proportion design of stalk and silk, which can further guide and optimize the experimental design of coke reduction and harm reduction of cigarette formula.