Abstract: To investigate the effects of cigarette structure parameters on the air flow field inside the cigarette, a computational fluid dynamics (CFD) method was adopted to simulate the air flow process inside a cigarette. The effects of viscous resistance coefficients of cigarette materials and cigarette length on the mouth end pressure drop and the ventilation rates of cigarette paper and filter were analyzed, and the correlation equations, which can quantitatively describe the coupling effect of cigarette structure parameters on the air field inside cigarette, were established. The results showed that: 1) The pressure drop was positively correlated with the viscosity resistance coefficients of cut tobacco, filter, cigarette paper and plug wrapper, the ventilation rate of cigarette paper was positively correlated with the viscosity resistance coefficients of cut tobacco and plug wrapper, and the ventilation rate of filter was positively correlated with the viscosity resistance coefficients of cut tobacco, filter and cigarette paper. 2) As the cigarette length decreased or the cigarette diameter increased, the pressure drop and the ventilation rates of the cigarette paper and filter decreased. 3) As the number of ventilation holes increased, the pressure drop and the ventilation rate of the cigarette paper decreased, while the ventilation rate of the filter increased. As the distance between the ventilation holes and the mouth end increased, the pressure drop and the ventilation rate of the cigarette paper increased, while the ventilation rate of the filter decreased. 4) The correlation coefficients of the established correlation equations were all higher than 0.93, and the relative errors between the predicted and measured values were small, which could accurately describe the coupling effect of cigarette structure parameters on the air flow field inside the cigarette.