Abstract: In order to clarify the flow field characteristics of the cigarette filter, the point cloud information of the three-dimensional structure of a cigarette filter was obtained by CT scanning method. After substantialization processing, a fluid domain calculation model for the cigarette filter was established, and the numerical simulation of the gas diffusion process was carried out. Based on the experiment of the cigarette filter draw resistance, the results of three-dimensional reconstruction simulation, semi-empirical formula and traditional porous media model were compared. The results showed that compared with the experimental values of the filter pressure drop, the deviation of the three-dimensional reconstruction simulation result was only 31.7%, while the deviations of the theoretical calculation and the calculation by the porous media model were 135.32% and 95.93%, respectively. The three-dimensional reconstruction numerical simulation method was more accurate in constructing the draw resistance model of the filter, thus providing a new approach to explore the flow field characteristics inside cigarette filters.